Optimized Caliber [Archive] - 6.5 Grendel Forum : : For the 6.5 Grendel Aficionado

stanc

08-24-2011, 07:45 PM

Here are the specs I would like to see, and I guarantee that soldiers and small unit leaders would welcome:

1) System replaces M249 SAW and M240 machineguns for dismounts
2) Cartridge offers ballistic improvements over 5.56 NATO in trajectory, wind drift and penetration of mud brick, cinder block, and vehicles at 500m
3) Cartridge weighs less than 7.62 NATO, allowing at least a 20% threshold increase in ammunition carrying capacity in linked form, with an objective of 30%...without losing any elevation trajectory or penetration of equal mediums at 700m
How about 37% lighter than 7.62 NATO, and 8% lighter than 6.8 SPC or 6.5 Grendel, with flatter trajectory than any of those?

For an optimized military cartridge, 6x41 looks really good to me. Not only for a new LMG, but also for conversion of 5.56 rifles.
http://68forums.com/forums/showthread.php?15855-6x41&p=154811&viewfull=1#post154811
http://i208.photobucket.com/albums/bb218/constructor2007/6x41.jpg

HANKA

08-24-2011, 07:57 PM

Stan, I wouldn't cry too much over such a cartridge, but the specs posted in the link would need to be verified in the real world. Every wildcatter's fantasy has amazing performance until independently verified under conditions and configurations which may not show it quite in the light the wildcatter would hope.

John

bwaites

08-24-2011, 08:05 PM

Hmmm....Same case capacity as the 6.8, but shooting a 95 grain bullet at velocities that are similar to the AR Turbo, which has more case capacity. I'm not convinced its going to work!

stanc

11-28-2011, 04:40 AM

Interesting Israeli 7mm "intermediate" cartridge discovered.

http://iaaforum.org/forum3/viewtopic.php?f=8&t=11781

stanc

12-02-2011, 06:46 AM

Thread on Tony Williams' forum about using a KelTec bullpup rifle to test and evaluate the 6.5/8/800 concept:

http://forums.delphiforums.com/n/mb/message.asp?webtag=autogun&msg=4861.1

LRRPF52

12-02-2011, 09:30 PM

That's funny, because I was just thinking about the Universal Infantry Cartridge Thread and I walked away thinking that the 800m and CQB requirement could be met with a bullpup with .260 Rem or 6.5x47 Lapua ballistics. If you used a polygonal rifled barrel, you could maybe increase the barrel life. Since the Grendel already will bite the heels of .260 Rem out of a bolt gun, I would lean towards the Grendel case with longer mag COAL, meaning a new magazine design entirely. The bullpup would also need a larger bolt geometry to take the pressures, since we are talking about a higher pressure cartridge no matter how you look at it. To get the pressures more moderate, you need to increase case capacity and that means larger mags, less mag capacity, etc.

With the magazine in the rear of the weapon, you do face certain prone profile limitations that aren't ideal, especially if you're using a magazine with more capacity than 20rds. I don't think the mag change issue is a huge deal, and ejection is solved with the forward eject system prototyped by the Soviets that everyone is copying now. The real hurdles that would need to be overcome would be ergonomic interface as to mag release and bolt catch/bolt hold-open with the firing hand.

The Tavor has addressed the selector control, but it has a mag release that requires two hands, and the bolt stop is at the toe of the butt of all places. I like bullpups, but have yet to see a real viable platform with the features I like, to include the above ergonomic interface devices that are standard on the AR.

To the layman, we are basically re-visiting the EM-2/.280 Enfield.

txgunner00

12-03-2011, 04:19 PM

Interesting but the 2900 does seem a bit optimistic.

stanc

12-03-2011, 09:44 PM

Interesting but the 2900 does seem a bit optimistic.
I think MV of the 6x41 has since been revised down to 2800 fps.

LRRPF52

12-04-2011, 05:05 AM

That is still good velocity. There aren't any military-grade projectiles for it, but it would be another wildcat for AR shooters. The 6mm AR requires only sizing down, while the 6.8 needs to be trimmed for length, then sized, has more powder, and more bullet selection for competitors since you can use longer VLD-types without taking case capacity, and still mag-length load.

6mm doesn't offer enough over 5.56 for 55gr-70gr performance out of an AR with FMJ pills, and doesn't have the retained energy a lot of people expect out of an LMG for 500-800m terminal performance, so that is why I lean to the idea that a 6.5mm in the 130-140gr class is ideal for a Multi-role LMG.

stanc

12-04-2011, 05:23 AM

6mm...doesn't have the retained energy a lot of people expect out of an LMG for 500-800m terminal performance, so that is why I lean to the idea that a 6.5mm in the 130-140gr class is ideal for a Multi-role LMG.
You may be right, but I don't see how you're going to get practical "green" bullets heavier than ~120gr.

And in order to attract attention of anybody in the military, won't it be necessary to demonstrate that a 6.5 LMG actually can deliver the required performance?

LRRPF52

12-04-2011, 08:30 PM

I would actually look more seriously at a 130gr projectile minimum for an LMG, if not 140gr like the x55 Swede used. Since COAL isn't an issue for keeping within an AR15 mag length/receiver, and you can design the bolt from the ground up as a high-strength component, and you won't be concerned with reloading the brass, a 130-140gr LMG military projectile is more than feasible, and can be launched at 2600-2700fps with the right powder specific to that loading after the RDT&E is done on it.

Then drop that into a constant-recoil LMG, and you have game day as far as capability is concerned. A 2600fps 140gr 6.5mm FMJ or MP projectile will start to out-gas a 147gr M80 at 300yds, even though it starts out 200fps slower. The 144 FMJ is another option that really smokes 7.62 at distances where GPMG's really come into play.

It's definitely worth pursuing in my book.

stanc

12-04-2011, 09:07 PM

I agree it's worth pursuing. It's just that, as presented, the idea raises a couple of questions:

You say that "a 130-140gr LMG military projectile is more than feasible." On what basis do you make that claim? It looks to me like the steel/copper and steel/steel construction being used in American, European, and Scandinavian "green" bullets will result in a ~120gr 6.5mm bullet the same length as the 120gr GMX (1.4"). That makes for a 5.3 L/D ratio. For a 130-140gr it would increase to the 5.8-6.8 range. Is that truly feasible?

AFAIK, the "constant recoil" principle has only been applied to 5.56mm machine guns. What evidence is there to show it is viable for more powerful cartridges, such as your 6.5 Grendel +P+ load? Do you know of any constant recoil 7.62mm machine guns?

ETA: The heaviest copper solid spitzer boattail I could find is a 128gr GSC. Note the very fast twist rifling required to stabilize the 1.51" projectile.

http://www.gsgroup.co.za/264128SP060.html

LRRPF52

12-05-2011, 07:27 PM

The constant recoil principle spans several different designs, and a wide caliber range. It is not beholden to any specific caliber, just as there are different operating systems, and recoil mitigation devices covering small bore up to artillery pieces. The Suomi Kp31 9mm SMG uses constant recoil. The 7.92x33mm German MP44/Stg44 uses constant recoil as well. I believe they are the first two shoulder-fired infantry weapons to have ever used it.

The 130-140gr weights are based on traditional bullet designs in FMJ's. A military looking for an affordable cartridge will not hold itself to environmental protection guises disguising economic warfare from within, as I suspect the "green" ammunition push to be, modeled after the restrictions on lead for fowl hunting, with no scientific basis for environmental protection, and a true agenda to disarm populaces via incrementalism. Since I don't see them fielding a "green" M80 any time soon, we needn't operate under the limitation that any future LMG cartridge must be "green". It would bankrupt current ammo budgets, which may be the goal of the EPA useful idiots in the hands of their Marxist overlords...

The 6.5x55 Swede has proven itself not only in decades of warfare, but across the game spectrum from medium-sized critters to large African species. An LMG duplicating 6.5x55 Swede ballistics, which has already been done actually if you look at the Swedish BAR's, is a proven system already from the muzzle-to-target standpoint. It just needs the platform built and fielded to an Army that prioritizes logic in its weapons procurement philosophy, not corruption and cronyism, so that pretty much rules out the US if business is as-usual in the Pentagon.

stanc

12-05-2011, 09:00 PM

The 130-140gr weights are based on traditional bullet designs in FMJ's. Since I don't see them fielding a "green" M80 any time soon, we needn't operate under the limitation that any future LMG cartridge must be "green".
M80A1 is being developed, and IIRC fielding is expected to begin in late 2012.

As I recall, "green" ammo is already in service in one or more Scandinavian countries, as well as the USA, and being planned for in the UK and Europe. IMO, to ignore the clear trend is, in the absence of evidence to the contrary, wishful thinking.

Also, where economics may prevail over environmental concerns, such as in the less affluent nations of Eastern Europe, the typical military bullet has a steel core. That type of construction results in a projectile just as long as a "green" bullet.

If your 6.5 LMG concept depends upon the use of lead-core heavy bullets in order to be viable, it seems to me you're severely reducing the chances of success.

LRRPF52

12-06-2011, 02:43 PM

The 6.5 LMG concept doesn't depend on a particular projectile material. In fact, the length of 6.5mm projectiles allows more options, unless one is relying on the case capacity of a larger, heavier cartridge like the 7.62 NATO or 7.62x54 Russian to suck up the extreme length of a longer solid projectile, which puts us back to the problem with GPMG's and their bulk/weight currently straining the maneuverability of dismounted infantry soldiers. It also reduces case capacity significantly in the x51 case. moving closer to a Grendel case capacity, so the law of diminishing returns pushes towards the smaller case and a smaller bore diameter anyway.

We already know that a 1.285" long Lapua 144gr will perform better for wind drift and penetration than a stubby M80 ball round, with significantly less muzzle velocity starting into the race. At distance, the 7.62 will lose all day long, with more recoil to deal with, and a much heavier gun.

I'm not under the illusion that logical weapons are the ones to get chosen, but I'm not going to push for a polished turd like the M9, SAW, M16A2, etc. I have a conscience and a gag-reflex.

JASmith

12-06-2011, 03:00 PM

As far as projo-length is concerned, the Grendel is far better suited for longer projectiles than choices like the 5.56 and 6.8. Further, our experiences with bullets like the Hornady 120 gr GMX and Barnes 130 gr TSX tell us these bullets will work in the Grendel -- and probably a lot better in the longer magazine length you describe. The 130 TSX has about the weight density and shape factor that would be seen in a copper-jacketed steel-core round. To be sure, the longer bullets have created some surprises, but these are readily overcome details, not show-stoppers.

LRRPF52

12-06-2011, 03:23 PM

Yes, the long projectiles aren't a big deal for a belt-fed LMG with a short case. The 120gr GMX ain't fitting in the Grendel/AR15 with much success, since it takes so much case capacity, but an LMG with a feed tray doesn't care what the AR15 can feed, and shouldn't. Even if we load them exactly the same, the linked ammo will come in cans linked, and ammo for carbines will come on stripper clips. It's been that way for a long, long time.

I certainly don't want Joes blasting away with bullets like the 120gr GMX in a CQB environment with multiple entry points and the fog of war. That would be insane to go into a house like that, but if the LMG gunners lit the place up before we went in, and supported us with shifting fire, that would be perfect. It would also let the SAW gunner duty position in the rifle squad reach out to where the M240 currently engages targets, in a blaster that is much less than half the weight of a 240, with a constant recoil system that even an X-Box junkie with wimpy muscle mass could track on target at 800m with suppressive and effective fire on his second burst, and keep it on-target. Stalky guys have a hard enough time doing that with a SAW at 200m now.

stanc

12-06-2011, 07:17 PM

The 6.5 LMG concept doesn't depend on a particular projectile material.
It certainly seemed like it does. All you've talked about is using 130-144gr lead-core FMJ bullets, and have refused to discuss using "green" projectiles.

I understand that you intend to load significantly longer than 5.56 mag length. That isn't the issue. My concern is that 130-140gr bullets with two-piece steel/copper (US/Europe), steel/steel (Scandinavia), or one-piece steel (Eastern Europe) cores will be too long in that weight range to be feasible, if only due to the stability factors.

As I noted in a previous post, the 128gr GSC is the heaviest solid spitzer boattail on the market, and it is 1.51" long, requiring rifling twists in the 6-7" range. That info indicates a 130-140gr "green" bullet or conventional steel-core projectile would be 1.6-1.8" long. That makes for an extremely long L/D ratio, unusual even for 6.5mm. I don't know what rifling twist would be necessary to stabilize such spears, but it looks like it'd be faster than 1:6.

stanc

12-06-2011, 07:51 PM

As far as projo-length is concerned, the Grendel is far better suited for longer projectiles than choices like the 5.56 and 6.8.
That's true for 6.8 only when limited by 5.56 mag length. Remove the mag length restriction, as Paul intends for his LMG, and 6.8 SPC becomes a viable option at least as good as - and possibly even better than - 6.5 Grendel.

bwaites

12-06-2011, 08:19 PM

That's true for 6.8 only when limited by 5.56 mag length. Remove the mag length restriction, as Paul intends for his LMG, and 6.8 SPC becomes a viable option at least as good as - and possibly even better than - 6.5 Grendel.

Not really, because the Grendel has a significant advantage in SD when using same weight projectiles. That increases barrier penetration. Since powder capacity is essentially the same, using same weight bullets the Grendel will have higher BC's and improved SD's.

HANKA

12-06-2011, 09:11 PM

It's a matter of balance. Bigger projectiles and more powder give more recoil, and we're back to where we started. Limitations must be understood and set . . . somewhere.

John

stanc

12-06-2011, 09:28 PM

Not really, because the Grendel has a significant advantage in SD when using same weight projectiles. That increases barrier penetration. Since powder capacity is essentially the same, using same weight bullets the Grendel will have higher BC's and improved SD's.
Yes, really.

SPC's smaller case diameter allows higher pressure for the same bolt thrust. Higher pressure = higher MV.

Without mag length limit, SPC can use heavier bullets to match Grendel's former BC advantage.

Heavier bullets at same or higher velocity = better penetration of barriers like concrete block.

With "green" (and steel-core) bullets, 6.5 may have a practical max weight of ~120gr, whereas for 6.8 it'd be ~130gr.

Then there is the question of reliable feeding of Grendel's short, fat case in a belt-fed machine gun. The SPC has a configuration much like that of cartridges that are proven to work.

Of course, the most critical aspect of a Grendel LMG is that it requires we ASS-U-ME viable disintegrating links can be designed. In contrast, no such assumption is necessary with the SPC case, which has dimensions compatible with the existing link design.

If testing (not just theory) were to prove 6.5mm bullets are truly better than 6.8mm projos, then IMO the prudent course of action would be to go with 6.5 SPC.

stanc

12-06-2011, 09:33 PM

It's a matter of balance. Bigger projectiles and more powder give more recoil, and we're back to where we started. Limitations must be understood and set . . .
I agree. Question is, what are those limits?

bwaites

12-06-2011, 09:41 PM

If you are designing a new chamber and rifle, then the bolt thrust issue is a moot point, you can run whatever pressure you designate as the ideal, and build the bolt assembly to match. The longer, skinnier 6.8 case requires a longer extraction movement, with the attendent larger recipricating issues, which creates at least as big a disadvantage as does the ability to make links work for the shorter, fatter case. We know that full auto is no issue with the Grendel because its been run that way in AR's by plenty of people with no complaints.

Heavier doesn't necessarily equal better penetration. At equal velocities, penetration also is affected by frontal area, so a bigger bullet that is heavier might have the same penetration as a lighter, but higher sectional density bullet. (Thats why elephant hunters shot 6.5's instead of bigger bullets, at least some of the time.)

And once again, using same weight bullets, the Grendel has a higher SD, and thus will penetrate better. With a lighter bullet with the same SD, it will also have less recoil, which is another factor in its favor.

Recent development has pretty conclusively shown that short powder columns are more efficient than long powder columns, as well.

BUT....we are arguing about this just to argue, because all of it is theoretical.

Where is JMB when you need him?

HANKA

12-06-2011, 10:22 PM

Question is, what are those limits?

A starting point is to ask: Are we OK with small arms that would be bigger and heavier than the current M4/M16 series? Longer cartridge overall lengths start a growth spiral.

John

P.S. One niggling point I had meant to make: I believe M855A1 is not ONLY copper and steel, but includes a bismuth alloy core under the steel penetrator. (I THINK it's bismuth!)

JASmith

12-06-2011, 11:05 PM

A starting point is to ask: Are we OK with small arms that would be bigger and heavier than the current M4/M16 series? Longer cartridge overall lengths start a growth spiral.

John

P.S. One niggling point I had meant to make: I believe M855A1 is not ONLY copper and steel, but includes a bismuth alloy core under the steel penetrator. (I THINK it's bismuth!)
We could start a poll, but I am reasonably sure that weight and bulk are anathema to the grunt, so he will be happy with the lightest one that works.

I've been closely following the 5.56 replacement debate for several years now, and know it has been going on for more than fifty years. The one constant is that those who have used the 5.56 in its design performance envelope swear by it. As long as the combat fits within that envelope, experienced combat veterans seem to be well-served by the cartridge. So, we get another indicator that folks would not be OK with bigger and heavier small arms.

The Grendel "toe in the door" results from the fact that, even in the jungles of Vietnam, there were times that terminal performance at longer ranges was shown to be less than desired. The back-fill in capability has been done with things like 7.62, Grenade launchers, mortar, artillery, and air assets.

LRRPF52 is suggesting that the grunt who uses a SAW or M240 to give team support for engagements beyond a couple of hundred meters could see a significant weight reduction while keeping pretty much the same terminal effects on targets as with the M240 by using a Grendel cartridge in a properly designed LMG.

-----

As for your question about M855A1, can we expand the question to include resulting ballistic coefficient? As I understand, a couple of different forms were looked at and reported on during the development. I think the early reporting was needed to garner support, but there seems to be less than detailed discussion about the final product, its design, and how well it performs.

stanc

12-07-2011, 12:10 AM

If you are designing a new chamber and rifle, then the bolt thrust issue is a moot point, you can run whatever pressure you designate as the ideal, and build the bolt assembly to match.
That's true, but less beefing up of the bolt and other components will be needed for a cartridge with less bolt thrust. That translates to increased durability and/or decreased weight.

The longer, skinnier 6.8 case requires a longer extraction movement, with the attendent larger recipricating issues, which creates at least as big a disadvantage as does the ability to make links work for the shorter, fatter case.
Do you seriously think that a 4mm longer extraction poses anywhere near the difficulties as design and development of a new link???

We know that full auto is no issue with the Grendel because its been run that way in AR's by plenty of people...
We know that 6.5 Grendel does full-auto fine in magazine-fed rifles. We do not know how it does in belt-fed machine guns.

Heavier doesn't necessarily equal better penetration. At equal velocities, penetration also is affected by frontal area, so a bigger bullet that is heavier might have the same penetration as a lighter, but higher sectional density bullet.

And once again, using same weight bullets, the Grendel has a higher SD, and thus will penetrate better.
The problem with that idea is, with the 5.56 mag length limit lifted (as in Paul's LMG concept), 6.8 SPC is not limited to bullets of the same weight. It could use bullets of the same SD, launched at equal or higher velocities.

stanc

12-07-2011, 12:24 AM

A starting point is to ask: Are we OK with small arms that would be bigger and heavier than the current M4/M16 series? Longer cartridge overall lengths start a growth spiral.
Paul wants to keep the M4 chambered for 5.56 NATO, so there wouldn't be a weight spiral for carbines. What he proposes is a special, long-loaded, high-pressure 6.5 Grendel solely for an LMG (and maybe DMR).

One niggling point I had meant to make: I believe M855A1 is not ONLY copper and steel, but includes a bismuth alloy core under the steel penetrator. (I THINK it's bismuth!)
The previous version (M855A1 LFS) did have a bismuth alloy slug behind the steel tip. However, that caused problems, so the current loading (M855A1 EPR) has a copper slug.

Below:

[Penetrator] [M855A1 LFS ------------------->] [M855A1 EPR ->
http://i129.photobucket.com/albums/p208/tpb2002/BismuthvsCopper.jpg

HANKA

12-07-2011, 12:45 AM

If you're OK with exceeding AR15 mag constraints, then all bets are off. Let the military define a set of requirements and design a cartridge to it.

The 6.5 Grendel's genius is the performance it gives from weapons currently sized for the 5.56 cartridge. One could, I suppose, make a pretty good case for the 65G as is, in terms of performance relative to size and recoil, even with a blank slate. And it's a case I'd be tempted to make if I had a fully developed 6.5 Grendel M855A1 analog. ;)

John

stanc

12-07-2011, 02:04 AM

The 6.5 Grendel's genius is the performance it gives from weapons currently sized for the 5.56 cartridge. One could, I suppose, make a pretty good case for the 65G as is, in terms of performance relative to size and recoil, even with a blank slate. And it's a case I'd be tempted to make if I had a fully developed 6.5 Grendel M855A1 analog.
Unfortunately, such a critter doesn't exist, and in any event, you most likely don't have any M855A1, either.

But, since performance should be relative as long as the same type bullets are used in each caliber, you ought to be able to make your case (if the premise is valid) via comparative testing with lead-core FMJ bullets in 5.56, 6.5 and 7.62 ammo. There's no need to wait for a 6.5 M855A1 analog. ;)

LRRPF52

12-07-2011, 04:17 AM

stanc

12-07-2011, 06:12 AM

With the 6.8, you would want to neck it down to 6.5mm, but a 6.5 SPC or 6.8 SPC with longer projectiles for an LMG would make a COAL close to 7.62 NATO. What I like about the Grendel case is that I can still have a relatively short COAL compared to 7.62, and that means more optimum space utilization on the soldier's load.
The difference in cartridge OAL would be only 0.16" for 6.5 SPC, and ~0.20" for 6.8 SPC. It's hard to imagine that such a tiny amount would be noticeable.

Even if it is, the other side of the coin is the increased bulk of the 6.5 Grendel case makes for a longer belt, or for fewer number of rounds in belts of the same length.

200 - 5.56 NATO
160 - 6.8/6.5 SPC
150 - 6.5 Grendel

The .277 projectiles require way more velocity to get them to do what a moderate velocity 6.5 will do...I learned that with the 140gr 6.5 Berger VLD for my .260 Rem versus the .277 140gr Berger VLD for my .270 Winchester: The .270 requires 250fps more muzzle velocity to match the .260 Rem at 1000yds, and the .260 still has it beat for wind deflection.
That's the same thing Bill said, except in different words. Again, nothing says 6.8 SPC must use the same weight bullet as 6.5 Grendel. The 6.8 can use heavier bullets with BC and SD comparable to those for 6.5, thereby achieving similar trajectory, wind drift, and retained energy.

These factors are what make the Grendel case more appealing to me for an LMG. The one possible advantage I see with the 6.8 case is the shoulder angle might be more conducive to feeding, but the inverted feed ramp of a belt fed would be tapered to articulate with whatever cartridge it was chambered in.
I don't view 6.5 Grendel's 30-degree shoulder as significant. After all, the 7.5 Swiss has a 28-degree shoulder, and it was used in belt-fed GPMGs for many years.

Far more critical is the issue everyone else wants to ignore: There is no empirical evidence to support the idea that viable disintegrating links can actually be developed for 6.5 Grendel. Those advocating a 6.5 Grendel LMG are assuming that proper links can be done. They may be wrong.

Variable

12-07-2011, 09:51 AM

Do you seriously think that a 4mm longer extraction poses anywhere near the difficulties as design and development of a new link???

We know that 6.5 Grendel does full-auto fine in magazine-fed rifles. We do not know how it does in belt-fed machine guns.

Again for the umpteenth time... LOL You have a problem with seeing a Grendel link. OK, I just accept that as your own personal quirk. I've shot plenty of belt feds, I instructed on belt feds, I own a belt fed, I've shoveled tons of links, and fixed belt feds when they broke. I take a Grendel round and look at a disintegrating 5.56 link... I see zero issues with modding it to work with the Grendel. It's only making different stamps for the manufacturing process. A non-issue to me really, but you disagree. I agree to disagree with you until the cows come home. If anything, the only thing I can see which would actualy boost your argument (IMO) would be if you shifted your attack to the difficulty of getting someone to actually MAKE Grendel links. There you'd have something to chew on IMO. LOL!!!:p;):D

stanc

12-07-2011, 10:12 AM

Again for the umpteenth time... LOL
Oh, come on. I'm sure it's been more than umpteen times. ;)

You have a problem with seeing a Grendel link. I take a Grendel round and look at a disintegrating 5.56 link... I see zero issues with modding it to work with the Grendel. It's only making different stamps for the manufacturing process. A non-issue to me really, but you disagree.
That's because to modify the design for the Grendel case would require reducing width of the link loops considerably. They are already pretty darn narrow along most of the loop, and even more so at the junctions between loops. Reduce the junctions any further and the link will become extremely thin and weak at those points. For that reason, I can't help being skeptical.

JASmith

12-07-2011, 01:42 PM

Again for the umpteenth time... LOL You have a problem with seeing a Grendel link. OK, I just accept that as your own personal quirk...I agree to disagree with you until the cows come home. If anything, the only thing I can see which would actualy boost your argument (IMO) would be if you shifted your attack to the difficulty of getting someone to actually MAKE Grendel links. There you'd have something to chew on IMO. LOL!!!:p;):D
Ditto!

HANKA

12-07-2011, 03:50 PM

Far more critical is the issue everyone else wants to ignore: There is no empirical evidence to support the idea that viable disintegrating links can actually be developed for 6.5 Grendel.

Stan, Stan, Stan. . . . Speaking for myself, I deliberately ignore this line of discussion because, to me, it's patently ridiculous and completely unworthy of comment. I have no idea why, in this day of space shuttles, high-definition TV, cell phones, and computers, that stamping a piece of sheet steel in a slightly different shape seems so daunting.

It's utterly . . . it, wow . . . it leaves me speechless.

John

Variable

12-07-2011, 04:33 PM

Oh, come on. I'm sure it's been more than umpteen times. ;)

That's because to modify the design for the Grendel case would require reducing width of the link loops considerably. They are already pretty darn narrow along most of the loop, and even more so at the junctions between loops. Reduce the junctions any further and the link will become extremely thin and weak at those points. For that reason, I can't help being skeptical.
Sure you reduce the width, and then you stamp them out of very slightly thicker sheet material. It's all to get the right tension while having enough strength. There really isn't anything unique about it. If anything, the lack of case taper makes it even simpler in a push through design.

stanc

12-07-2011, 05:48 PM

Chris, you make it sound so simple. "Just reduce the width, and stamp them out of thicker sheet material." Well, the M27 link loops are so narrow that it makes me wonder if they actually can be reduced enough for proper operation with a cartridge that is substantially fatter and heavier. Width of the loops has to be cut back quite a bit for the Grendel case shoulder to extend enough ahead of the link so as to contact the cartridge stop.
http://www.inetres.com/gp/military/infantry/rifle/5.56mm/M27_links.gif
http://wapedia.mobi/thumb/d920507/en/fixed/470/313/Ammunition_Belt_5.56_mm.jpg?format=jpg

John, stamping a piece of sheet steel in a slightly different shape is hardly a daunting task. The problem is reducing the dimensions to the extent necessary, while retaining the requisite strength and flexibility.

You guys are going on faith, a belief that it can be done.

I prefer to have proof, or at least convincing evidence.

stanc

12-07-2011, 06:10 PM

http://i381.photobucket.com/albums/oo255/FEDE_EL_SOMALI/2-28.jpg

bwaites

12-07-2011, 06:30 PM

Hmmm....Stan, have you read John Moses Browning's biography?

stanc

12-07-2011, 06:40 PM

If I have, it was too long ago to remember, Bill.

Wherefore doest thou ask?

bwaites

12-07-2011, 07:23 PM

I've just finished re-reading it, and I'm struck by his ability to believe that whatever needed to be done COULD be done, and then his decision regarding MAKING what could be done a reality.

OF course, I also agree with this statement:

It's difficult to take an "anti-faith" position. There's no pejorative connotation of the word faithful. The only time "faith" seems negative is when it's prefaced by the word "blind." But blind faith is the only kind of faith there is. In order for someone's faith to be meaningful, it has to be blind. Anyone can believe a hard fact that everyone already accepts. That's easy. If you can see something, you don't need faith. Faith in the seeable is meaningless. But meaningful faith is dangerous. It simplifies things that aren't simple.

The words aren't mine, they are Chuck Klostermans, and they weren't written about weapons, but about a football player. BUT, they still are true. Nothing happens without an initial faith that it CAN happen. JMB was perhaps the ultimate believer in that with regards to weapons design. He had faith that he could make it happen. That faith is the difference in what he accomplished and what EVERY other gun maker accomplished. No other gun designer has ever come up with even 5 unique designs, Winchester patented 4 or more a YEAR for the time that Winchester was his sole market, and when he moved on, he kept Remington, FN, and Colt busy producing weapons that didn't compete with each other and were unique. Everyone said no automatic, dependable weapon could be manufactured, they would destroy themselves. So he invented a machine gun that worked, then he invented another, and another. His 1917 watercooled fired 20,000 rounds without failing at the demonstration, then he fired ANOTHER 20,000 without it failing just to see if it would!

MY point is this, IF there comes a time to need 6.5 Grendel links, they will be manufactured, and they will work. It's not nuclear physics, and todays metallurgical geniuses will find a way. Heck, I have eyeglasses that have a metal temple piece that I can bend in a circle and it goes back to its correct shape, every time. It's less than 1/16" in width, I have no doubt that making disintegrating links will be nowhere as difficult as that!

I have faith it can be done, if its needed. I'll need proof when I need the links.

bwaites

12-07-2011, 07:34 PM

A toothpaste factory had a problem: they sometimes shipped empty boxes, without the tube inside. This was due to the way the production line was set up, and people with experience in designing production lines will tell you how difficult it is to have everything happen with timings so precise that every single unit coming out of it is perfect 100% of the time. Small variations in the environment (which can’t be controlled in a cost-effective fashion) mean you must have quality assurance checks smartly distributed across the line so that customers all the way down to the supermarket don’t get ticked off and buy another product instead.

Understanding how important that was, the CEO of the toothpaste factory got the top people in the company together and they decided to start a new project, in which they would hire an external engineering company to solve their empty boxes problem, as their engineering department was already too stretched to take on any extra effort.

The project followed the usual process: budget and project sponsor allocated, RFP, third-parties selected, and six months (and $8 million) later they had a fantastic solution on time, on budget, high quality and everyone in the project had a great time. They solved the problem by using high-tech precision scales that would sound a bell and flash lights whenever a toothpaste box would weigh less than it should. The line would stop, and someone had to walk over and yank the defective box out of it, pressing another button when done to re-start the line.

A while later, the CEO decides to have a look at the ROI of the project: amazing results! No empty boxes ever shipped out of the factory after the scales were put in place. Very few customer complaints, and they were gaining market share. That's some money well spent! he says, before looking closely at the other statistics in the report.

It turns out, the number of defects picked up by the scales was 0 after three weeks of production use. It should've been picking up at least a dozen a day, so maybe there was something wrong with the report. He filed a bug against it, and after some investigation, the engineers come back saying the report was actually correct. The scales really weren't picking up any defects, because all boxes that got to that point in the conveyor belt were good.

Puzzled, the CEO travels down to the factory, and walks up to the part of the line where the precision scales were installed.
A few feet before the scale, there was a $20 desk fan, blowing the empty boxes out of the belt and into a bin.

Oh, that, says one of the workers, one of the guys put it there 'cause he was tired of walking over every time the bell rang.

Kikn

12-07-2011, 08:07 PM

HANKA

12-07-2011, 08:22 PM

You guys are going on faith, a belief that it can be done.

Guilty as charged. I have faith that the engineering talent that can "float" a 200-ton 747 in the air can somehow figure out 6.5 Grendel disintegrating links.

John

P.S. Bill, great story. Classic!

JASmith

12-07-2011, 08:37 PM

In this circumstance, the engineering pointers are obvious and people experienced in similar projects say it's doable. Further, they even give us an idea of how much it will cost.

So, with people more experienced in this field than I saying its doable, my faith on this topic is easy to feel!

One would hope that it won't be much more than installing a $20.00 fan at the right spot. Remember, however, the engineering and development effort that was used to make that fan a reliable and inexpensive product was a whole lot more than $20.00!!

This is part of why few of us are saying that the project won't involve a surprise or two for the developers, but the surprises are much of the fun of doing new things!!!

stanc

12-07-2011, 08:40 PM

Nothing happens without an initial faith that it CAN happen.
That's just not true. In my personal experience, as well as observation of others, things typically happen more from actions based on knowledge and experience than on faith that it can happen.

JMB was perhaps the ultimate believer in that with regards to weapons design. He had faith that he could make it happen. Everyone said no automatic, dependable weapon could be manufactured, they would destroy themselves. So he invented a machine gun that worked, then he invented another, and another. His 1917 watercooled fired 20,000 rounds without failing at the demonstration, then he fired ANOTHER 20,000 without it failing just to see if it would!
Perhaps you should read about Hiram Maxim. He invented a reliable, watercooled machine gun 20 years before Browning created the M1917, and he did it with black powder ammo!

Also, Browning's first belt-fed -- the M1895 "potato digger" -- incorporated a ridiculously complex mechanism to circumvent the patent on gas operation invented by (Guess who?) none other than Hiram Maxim.

MY point is this, IF there comes a time to need 6.5 Grendel links, they will be manufactured, and they will work.

I have faith it can be done, if its needed. I'll need proof when I need the links.
Well, I know there are some things that simply aren't doable with the technology available at the time. And since I'm not a man of faith, I require evidence that something can be done before I'll advocate it.

I sincerely hope that y'all are right, and disintegrating links for 6.5 Grendel are just a matter of $$$. But, it's difficult for me to argue for something that's currently no more than theoretical possibility.

stanc

12-07-2011, 08:55 PM

Nothing happens without an initial faith that it CAN happen.
That's just not true. In my personal experience, as well as observation of others, things typically happen more from actions based on knowledge and experience than on faith that it can happen.

JMB was perhaps the ultimate believer in that with regards to weapons design. He had faith that he could make it happen. Everyone said no automatic, dependable weapon could be manufactured, they would destroy themselves. So he invented a machine gun that worked, then he invented another, and another. His 1917 watercooled fired 20,000 rounds without failing at the demonstration, then he fired ANOTHER 20,000 without it failing just to see if it would!
Perhaps you should read about Hiram Maxim. He invented a reliable, watercooled machine gun 20 years before Browning created the M1917, and he did it with black powder ammo! Also, Browning's first belt-fed -- the M1895 "potato digger" -- incorporated a ridiculously complex mechanism to circumvent the patent on gas operation invented by (Guess who?) none other than Hiram Maxim.

MY point is this, IF there comes a time to need 6.5 Grendel links, they will be manufactured, and they will work.

I have faith it can be done, if its needed. I'll need proof when I need the links.
Well, I know there are some things that simply aren't doable with the technology available at the time. And since I'm not a man of faith, I require evidence that something can be done before I'll advocate it.

I sincerely hope that y'all are right, and disintegrating links for 6.5 Grendel are just a matter of $$$. But, it's difficult for me to argue for something that's currently no more than theoretical possibility.

bwaites

12-07-2011, 08:59 PM

That's just not true. In my personal experience, as well as observation of others, things typically happen more from actions based on knowledge and experience than on faith that it can happen.

We could argue this point until the sun refuses to rise. But without the faith to try something new, there would be NO KNOWLEDGE OR EXPERIENCE. As my dad taught me many years ago, "knowledge and wisdom come from experience, and most of that experience is liable to be of the bad type."

Perhaps you should read about Hiram Maxim. He invented a reliable, watercooled machine gun 20 years before Browning created the M1917, and he did it with black powder ammo!

Yes, and Maxim produced exactly ONE weapon that became widely used.

Also, Browning's first belt-fed -- the M1895 "potato digger" -- incorporated a ridiculously complex mechanism to circumvent the patent on gas operation invented by (Guess who?) none other than Hiram Maxim.

Well, I know there are some things that simply aren't doable with the technology available at the time. And since I'm not a man of faith, I require evidence that something can be done before I'll advocate it.

I sincerely hope that y'all are right, and disintegrating links for 6.5 Grendel are just a matter of $$$. But, it's difficult for me to argue for something that's currently no more than theoretical possibility.

Ah, the M1895 Potato Digger. Yep, complex. So complex it was designed and built in a workshop in Ogden, Utah before the turn of the 20th century, using tools that were crude even by the time, some of which were his father Jonathan Ogden's!

And its difficult to me to argue against something which is so inherently easy and cheap to produce...if there were a demand.

Do you believe that Armstrong walked on the Moon? If so, please tell me how you arrived at that belief.

stanc

12-07-2011, 09:07 PM

In this circumstance...people experienced in similar projects say it's doable.
IIRC, those people were commenting on manufacture of links. AFAIK, none of them have ever been involved in design and development of metallic links.

Get people who do have such experience, give them an M27 link, 5.56 NATO and 6.5 Grendel cartridges, plus the engineering drawing I posted earlier, and see if they think it's feasible to reduce the link loop dimensions enough to work with 6.5 Grendel.

stanc

12-07-2011, 09:35 PM

We could argue this point until the sun refuses to rise. But without the faith to try something new, there would be NO KNOWLEDGE OR EXPERIENCE.
Again, that's just not true. I myself have tried many things new to me, and faith was never a factor.

Yes, and Maxim produced exactly ONE weapon that became widely used.
That isn't relevant. Your post was "everyone said that no automatic, dependable weapon could be manufactured, they would destroy themselves," so Browning invented a machine gun that worked. The truth is that Maxim had already "invented a machine gun that worked," and he did it years before JMB.

Ah, the M1895 Potato Digger. Yep, complex. So complex it was designed and built in a workshop in Ogden, Utah before the turn of the 20th century, using tools that were crude even by the time, some of which were his father Jonathan Ogden's!
Maxim's gas piston system was simple, straight-line operation. Browning's "potato digger" had hinges, levers, and other crap that was indeed quite complex compared to Maxim's simple, elegant design. And Maxim's basic design is still used today, whereas Browning's version hasn't been made for about 100 years...

And its difficult to me to argue against something which is so inherently easy and cheap to produce...if there were a demand.
I've never said that metallic links aren't cheap and easy to make. The question I have is if they can be designed and developed, considering the changes that would be needed to fit the 6.5 Grendel case.

Do you believe that Armstrong walked on the Moon? If so, please tell me how you arrived at that belief.
<sigh> As I've said many times before, I consider belief to be illogical behavior, therefore I refrain from engaging in it.

bwaites

12-07-2011, 10:31 PM

"sigh" it's a simple question, yes or no?

stanc

12-07-2011, 11:52 PM

It is a simple question, but its premise is erroneous. I cannot answer yes or no, because I neither believe nor disbelieve.

bwaites

12-08-2011, 12:09 AM

It is a simple question, but its premise is erroneous. I cannot answer yes or no, because I neither believe nor disbelieve.

LOL!! There is no premise, the simple fact is that you are aware that man has walked on the moon, but are unwilling to acknowledge that acceptance because you well know that it requires faith, which you deny is a principal in your life.

I apologize for creating the trap.

Back to your regularly scheduled programming.

stanc

12-09-2011, 09:39 PM

LMG Cartridges (Size comparison)

5.56 NATO / 6.5 Grendel / 6.8 SPC / 7 UIAC / 7.62 NATO

bwaites

12-09-2011, 10:36 PM

Stan, to answer your question, I'm not sold on any of them, and I don't believe we will see acceptance of any of them, at least as general issue weapons.

I think the next military small arms system will NOT be brass (or steel) cased.

My belief is that it will be 6.5 to 7mm in caliber.

This, of course, is completely dependent on the worlds governments ability to actually still wage war. After todays announcement of an agreement in principle by the EEU (minus Great Britain), I suspect that large scale development of small arms systems for government use (at least WESTERN governments) may be a thing of the past, and that we may be headed down a rat hole very rapidly. Of course, some people think I'm optimistic!

LRRPF52

12-09-2011, 10:48 PM

Here's a good video that shows the importance of ammunition capacity and maneuverability. Also notice how the ATPIAL is dangling from his M4. Fog of war in broad daylight against an enemy in his own backyard.

http://www.youtube.com/watch?v=50bRYx8qCTE&feature=fvst

stanc

12-09-2011, 11:33 PM

Here's a good video that shows the importance of ammunition capacity...
How? As far as ammo capacity is concerned, I saw nothing in the video to indicate they would've been handicapped by being armed with 6.5-7mm carbines with magazines of 25-rd capacity.

LRRPF52

12-10-2011, 05:45 AM

How? As far as ammo capacity is concerned, I saw nothing in the video to indicate they would've been handicapped by being armed with 6.5-7mm carbines with magazines of 25-rd capacity.

One of the biggest things on small unit leader's minds is how much ammunition they have among the Team, Squad, or Platoon. You may not have picked it up, but you can hear one Joe give his ACE report as only having 100rds, and they were barely into the fight. If you have pushed the FLOT (Forward Line of Own Troops) to the extent that there is a vulnerable gap between you and your supporting elements to the rear, if any, you start to become hyper-aware of your unit's ammo status, believe me.

You don't want to be left out flappin' in the wind like sitting ducks, so this soldier and small unit-level logistics constraint is a very real factor for dismounts. Having a larger caliber carbine or rifle would guarantee the following:

1) Less ammo capacity per space/weight
2) Less maneuverability
3) Less capacity/willingness to pursue the fight according to logistics limitations

Handicapped

You can also see how having a different caliber for all the riflemen would be quite meaningless, and how important organic indirect assets are, like the grenade launchers. It is very difficult to get into a good firing position in these scenarios, since that will become a bullet magnet really quick. They were discussing a squad attack battle drill, where one element maneuvers as the other lays a base of fire, but there seemed to be a lot of hesitation, when it needs to be executed with little or no specific instructions.

5.56 = longevity to press the fight, since there is more capacity to carry ammo. Could this unit have been well-served with DMR's? Probably. Maybe they had them, and we just didn't see it. Either way, they would not have the endurance to press the fight if they had limited capacity. Carry a basic load of and intermediate cartridge, then carry one in 5.56, and it will start to make sense as you make initial contact, then maneuver to the next position, then do it again, then check your status to see you have 3 mags left, which is time to slow down and think about where you are, where your support is, etc.

Try that with riflemen carrying 7.62 NATO rifles and they are spent really quick. Same goes for AK's, although you can carry a little bit more ammo with the AK compared to 7.62 NATO battle rifles. Now a DMR tasked to provide discreet support with well-aimed fire at targets of opportunity is one thing, your Joes with carbines need to press the fight as these guys were. This is why I like the 8x30rd magazines bare minimum basic load for Infantry, although I personally carried more without issue.

To match that load with 7.62, you would need 12x20rd mags, which is not feasible with many genotypes other than 6ft+ Northern Germanic descendents of Vikings, Slavs, Pacific Islanders, and other large-statured, high muscle-density men with a warrior spirit.

HANKA

12-10-2011, 02:14 PM

If it were decided that both an intermediate cartridge, call it the 6.5 Grendel, and 30-round magazines were desirable, I'd add a half-inch to the length of a redesigned 65G mag so that we now have 30-round 65G mags and call it good. Yes, we'd next have to deal with the problem of the extra weight.

John

JASmith

12-10-2011, 02:56 PM

If the Grendel were already the service cartridge, going to the varmint cartridge would likely not happen because folks would see the small number extra rounds argument not being enough to be worth the bother.

This is a corollary to the observation that the round-for-round effectiveness improvement realized by going to the Grendel is not sufficient to warrant replacing the 5.56 NATO.

I have reluctantly come to agree with LRRPF52. Our best chance for seeing a new military cartridge is in the LMG.

LRRPF52

12-10-2011, 06:27 PM

Yes, the Marines maneuvered and fought for a while against the enemy in the early days of the Vietnam War, but then their combat endurance was significantly increased with the adoption of the M16. The weight and length handicap of the M14 was one of the main factors in adoption of the M16, as was the increased ammunition capacity.

I can't stress enough how important magazine capacity is among dismounted infantry units. As a kid, I remember reading every LRRP, SF, Force Recon, SEAL, and first-person account of deployments to Vietnam. In one book, a LRRP described a particular firefight when his team had been compromised....

"I was down to 10 mags...." That was 200 rounds back then (10x20rd mags). That made a very distinct impression on me, since I had been collecting TA-50 from early childhood, and had my own full set of LC-1 ALICE gear, knowing full well what space would be taken up with 200rds of ammo.

Units equipped with M14's for every rifleman were extremely limited in their ability to press the fight...basically, you might make two bounds and you're done, at which point in time you have to stay in place and let the trail unit by-pass you to press the fight, as you wait for a re-supply. This creates more demand on number of bodies to press the fight, lulls in fire that allow the enemy to escape, and confusion as the spent unit tries to pass on enemy disposition, direction, and distance to the passing unit.

The caliber used by riflemen to press the attack doesn't warrant anything larger because they are already closing with the enemy as a numerically-superior force. Most of the fire is effective because of psychological persuasion, especially since riflemen don't have a ton of practical marksmanship training.

Another over-looked factor is how disorienting large-caliber muzzle blast is to your buddies left and right. 5.56 is the most minimal offender in this respect, but is still somewhat of a problem to be dealt with in close proximity to friendlies who are trying to keep the enemy's location and movements fixed, which is a fleeting game with very little positive results usually.

stanc

12-11-2011, 02:32 AM

Another over-looked factor is how disorienting large-caliber muzzle blast is to your buddies left and right. 5.56 is the most minimal offender in this respect, but is still somewhat of a problem to be dealt with in close proximity to friendlies who are trying to keep the enemy's location and movements fixed, which is a fleeting game with very little positive results usually.
AH!!! MY EARS!!! (3:56)

http://www.youtube.com/watch?v=y4N2Xz5uICE

LRRPF52

12-11-2011, 02:38 AM

The question is: How long are we willing to milk the longevity out of 7.62 NATO? Is there any receptiveness to replacing it, given its entrenchment in vehicle-mounted systems, and favorable barrel life?

The reality is that 7.62 NATO will be around for at least the next 10-15 years at a minimum, and is not likely to be looked at as a problem due to the mistaken thinking that carbines & 5.56 are broken. As the bean-counters and corrupt procurement vultures try to replace 5.56, they meet immediate institutional resistance from Special Operations units in the US, England, Australia, Northern Europe, and Eastern Europe. Even the majority of combat arms troops report that 5.56 does what it is intended to do, and state satisfaction with it.

It's very difficult to show the military what it needs, because whoever is making that call has their own idea of what is needed. I think the biggest potential benefits to dismounted Infantry would be a totally new LMG concept as I have described, a multi-shot grenade launcher like the Marines have adopted, and a platoon-level organic indirect fire asset that is precision-guided: basically a small mortar that the lead fire team can lase onto target. That would be a big game-changer. No need to dial-in the tube...just point in the general direction of the enemy and let the lead team guide the munition. Air-burst and other types of warheads would be great for a fleeting enemy of dismounts in the open.

LRRPF52

12-11-2011, 03:04 AM

AH!!! MY EARS!!! (3:56)

http://www.youtube.com/watch?v=y4N2Xz5uICE

Great video....probably one of the best I've seen so far. Several of these SASR guys are using Knight's QD suppressors on their M4A1's. It's a bit nose heavy with the 14.5" barrel, which is why the CQBR uppers came out, but not everyone has those. Remember: These guys' country uses a licensed copy of the Steyr AUG as its service rifle...so why are they using M4A1's, and in 5.56 NATO to boot?

There were a lot of things one could learn from watching just the first 1:45 of that video. About 6 years of training and experience was put into play in just those 105 seconds...their procedures in the air, reacting to contact before they even touched down, use of cover and concealment, muzzle discipline, employment of the 203, approaching the objective and how to favor your approach to a structure.

Excellent video really. Only thing that would be nice to have would be a thermobaric SMAW-D, and just turn that turd hut into dust, but I digress.

The hearing loss issue just illustrated what I was talking about, even with electronic muffs. A larger bore weapon is much worse in close proximity. I can't really hear much of anything when my left ear is up when my right ear is on the pillow, because of an AK burst within 3ft of my left ear in 1995.

Regular units will not be a good place to issue suppressors, because of the associated problems that occur with them if not attached and maintained carefully...i.e. baffle strikes, baffle fatigue, "loss" of items by Joe, etc. There was a big push within the past 7 years to issue a can to every Joe, and it went away quickly. A Grendel carbine would only increase the hearing loss issue.

LRRPF52

12-11-2011, 03:38 AM

Here's the video I meant when I heard the guy say "I'm down to 100rds.", which is very common when you press the fight.

http://www.youtube.com/watch?v=KdcNWW7sFyk&feature=related

stanc

12-11-2011, 04:29 AM

It's very difficult to show the military what it needs, because whoever is making that call has their own idea of what is needed. I think the biggest potential benefits to dismounted Infantry would be a totally new LMG concept as I have described...
It might help if you could show them the difference. I know that the CQM videos you posted made a far bigger impression on me than all of the forum posts on the controllability issue. However, for this issue it would require building your proposed 6.5 LMG, which would be quite an expensive undertaking.

...a multi-shot grenade launcher like the Marines have adopted, and a platoon-level organic indirect fire asset that is precision-guided: basically a small mortar that the lead fire team can lase onto target. That would be a big game-changer. No need to dial-in the tube...just point in the general direction of the enemy and let the lead team guide the munition. Air-burst and other types of warheads would be great for a fleeting enemy of dismounts in the open.
Those sound like very good ideas. Guided mortar rounds have been developed in 81mm and 120mm. Doing the same for 60mm would be more difficult, but may be technically possible. The challenge would be convincing the bean counters that it'd be worth the cost.

stanc

12-11-2011, 04:59 AM

Great video....probably one of the best I've seen so far. Several of these SASR guys are using Knight's QD suppressors on their M4A1's. It's a bit nose heavy with the 14.5" barrel, which is why the CQBR uppers came out, but not everyone has those. Remember: These guys' country uses a licensed copy of the Steyr AUG as its service rifle...so why are they using M4A1's...
I don't know for certain why, but I think the reasons you've given sound logical: weight, size, handling, ergonomics, etc.

...and in 5.56 NATO to boot?
Ah, I can answer that in one word, and it has nothing to do with controllability. It's logistics, pure and simple. They use 5.56 NATO because it's the standard caliber for Western nations.

If the US had fielded the M16 in 6.5 Grendel back in the 1960s, that cartridge would've then been adopted by NATO in the 1970s. The M4A1 carbine would today be chambered in 6.5 NATO, and that's what the spec ops guys would be using, not 5.56x45.

Also, you would have had part of your wish fulfilled: FN would've made the Minimi in 6.5 NATO, which means the M249 would have had sufficient performance to replace the M60 as was originally planned. There would've been no requirement to create and field the heavy M240B. Everyone would be using 6.5 LMGs for infantry, and 7.62 NATO would have faded away long ago.

So, in this alternate timeline you wouldn't be here arguing for a 6.5 LMG, you'd be on m4carbine.net calling for M4 carbines to be converted from 6.5 NATO to .223 Remington... ;)

stanc

12-11-2011, 07:17 AM

Here's the video I meant when I heard the guy say "I'm down to 100rds.", which is very common when you press the fight.
Okay, I can hear it there. Except it appears to me it is the M240 gunner who says that, not one of the riflemen.

Even so, you have a good point. I recall reading (on the old forum?) of a Marine veteran of combat in Vietnam who attributed his unit's survival in some battles to the large number of rounds that could be carried with the M16.

Tony Williams

12-11-2011, 07:20 AM

Guided mortar rounds have been developed in 81mm and 120mm. Doing the same for 60mm would be more difficult, but may be technically possible. The challenge would be convincing the bean counters that it'd be worth the cost.

Actually, not a problem. The current ATK and GD-OTS guided mortar rounds use standard bombs with a fuze/guidance unit screwed in the standard fuze aperture. This will fit in 60mm mortar bombs as well. The only issue will be whether the cost of the fuze is worth it for the small bang - it might be, for arming small UAVs for instance (which is where the current interest in guided 81mm bombs comes from).

stanc

12-11-2011, 06:41 PM

I have reluctantly come to agree with LRRPF52. Our best chance for seeing a new military cartridge is in the LMG.
For the sake of discussion, let's assume that's true.

What course(s) of action can we take to advance the idea?

LRRPF52

12-12-2011, 03:52 AM

For the sake of discussion, let's assume that's true.

What course(s) of action can we take to advance the idea?

Prototype, RDT&E, then demo against 7.62 NATO GPMG's in scenarios ranging from Close Combat to traditional long-range machinegun transition ranges, plus barrier defeat demonstrations. The biggest hurdle is to get them to ask for it, rather than show them it's needed and have them say, "Yeah, nice system. We'll give you a call."

stanc

12-12-2011, 05:56 PM

Prototype, RDT&E, then demo against 7.62 NATO GPMG's in scenarios ranging from Close Combat to traditional long-range machinegun transition ranges, plus barrier defeat demonstrations.
That's a good summary of what needs to be done in total, but we'd need at least a six-figure budget for all that.

What I'm asking is what can we do, with the limited resources available to any of us?

stanc

12-20-2011, 11:15 PM

All of the creative thinkers in this forum, and not one doable idea on how to make this happen???

sgt_murf

12-28-2011, 07:20 PM

To the layman, we are basically re-visiting the EM-2/.280 Enfield.

Ya noticed that too????? aka .280 British version one is realllllll close to the Grrrrr
But I figured I would get FLAMED and BBQ over mentioning it.......... wait why is everyone holding those torches

JASmith

12-28-2011, 09:32 PM

At the risk of getting some of that toasty warmth myself, the difference between the .280 and our favorite is that the 6.5 does it with a light enough bullet to really separate it from the .30 caliber in terms of ammunition weight and recoil.

HANKA

12-29-2011, 09:25 PM

Article on full-auto (http://www.military.com/news/article/army-wants-full-auto-for-accuracy-not-rock-n-roll.html?ESRC=eb.nl) requirements.

John

Variable

12-30-2011, 04:41 AM

Article on full-auto (http://www.military.com/news/article/army-wants-full-auto-for-accuracy-not-rock-n-roll.html?ESRC=eb.nl) requirements.

JohnLong overdue in my book. Dual disconnectors make for a very sucky trigger pull. I was happy to scrape up a 4 position selector for my registered sear when I first got it (I'd never fired a burst contraption before). I couldn't pull it out quick enough after I tried it.

Burst length selector:http://www.ketrin.co.uk/blog/wp-content/uploads/2010/10/IndexFinger.jpg

stanc

12-30-2011, 05:37 AM

Article on full-auto (http://www.military.com/news/article/army-wants-full-auto-for-accuracy-not-rock-n-roll.html?ESRC=eb.nl) requirements.
Hmm. I'm positive I read that very same article months ago.

The Army’s senior leadership decided to start issuing M4A1s last year...
Huh? The Army began issuing M4A1s back in 2006!

Is military.com caught in a time warp, or something? :confused:

LRRPF52

12-30-2011, 07:53 PM

If they combine that with the SOPMOD Block II handguards, they'll be headed in the right direction. I would also like to see more mini red dot sights for those using dots, and 1-4x or 1-6x for those with magnified optics.

On another note, I've been working with a replica of the KAC PDW, and the small size of the mags for the 6x35 cartridge have really got me thinking about the logistics advantages riflemen would have with that cartridge. I could carry 18 mags easily, they are so small. If you pushed the 65gr 6mm projectile out of a 16" barrel, I bet you could get around 2800 fps. Do an 18" bullpup and you'd get maybe 2860 fps, but that's assuming a linear return on barrel length.

Have LMG gunners and DM's with Grendels, and riflemen with the 6x35, and you could see a significant logistics chain longevity increase over the 5.56/7.62 system. I think powder, case, and projectile technology are to the point where we could see gains over both legacy cartridges for an enhanced 2-caliber system. You have got to see how small these KAC PDW 30rd mags are, and that thing spits out a 6mm projectile from an 8" or 10" barrel with substantial energy.

JASmith

12-31-2011, 12:56 PM

I don't need to run calculations to tell that, for the same velocity, a 65 gr 6mm bullet will be less effective than a 62 gr 5.56 bullet. This is certainly true of barrier defeat and is true in wound channel generation.

My impression is that, absent an implementation in a weapon that clearly satisfies the size, weight, and ergonomic needs of the rifleman or for support troops, that a debate on this cartridge will go much the same way as all the other 5.56 replacement discussions.

Bottom line, the weapon/cartridge combination trades a little terminal effectiveness for slightly increased round count and smaller weapon, BUT not enough to make a compelling difference.

stanc

04-07-2012, 07:21 AM

Is this hinting at military use of 6.8 SPC in the near future?

"The military/LE market is...very deliberate, slow to change.

It took this long for 6.8 to turn a corner that needed to be turned.

6.8 in testing...is by far the most capable and somewhat perfect round for modern military and LE missions. Now it will be affordable and competitive with 5.56.

This ammo is loaded to military specifications with crimped sealed primers, case necks, visible annealing."

(Also note the 30-rd 6.8 P-Mag.)

http://forum.lwrci.com/viewtopic.php?f=2&t=11314

Tony Williams

04-07-2012, 10:14 AM

I very much doubt it. I can't see anything being adopted as a straight replacement for 5.56mm - the military has too much invested in it and refuses to admit that there's any problem with it.

What there is interest in is a cartridge which can reach out as far as 7.62mm while weighing a lot less. The 6.8mm Rem can't deliver this - it doesn't have the range - but the 6.5mm Grendel could. Of course, if such a cartridge were adopted to replace the 7.62mm MGs and rifles at squad level, there wouldn't be any point in carrying the 5.56mm as well, would there?

LRRPF52

04-07-2012, 03:47 PM

There is still plenty reason to have carbines chambered in 5.56, since a Grendel load that is capable of replacing the 7.62 NATO for range and penetration will have all the effects you don't want at close range:

Too much recoil
Too much penetration for Close Quarters
Too much weight penalty on the rifleman

You would need a separate light loaded round.

stanc

04-07-2012, 06:28 PM

I can't see anything being adopted as a straight replacement for 5.56mm - the military has too much invested in it and refuses to admit that there's any problem with it.
That's been the case so far. However, there's a post today on 68forums that seems more than just a hint at military use:

"These mags were not developed for the civilian market.

The design criteria: 1) will not lock into a standard magwell for those units that run 6.8 alongside 5.56 and 2) match the magazine geometry of 5.56 with a fatter cartridge for improved feeding reliability.

In addition, at my suggestion, the maximum COAL was increased...

There is a lot more to this than is public at this time. More information should be released in the next few weeks."

http://68forums.com/forums/showthread.php?28128-Federal-6.8-Ammo-and-Polymer-Mag&p=298959&viewfull=1#post298959

bwaites

04-07-2012, 08:25 PM

So, now there will be ANOTHER 6.8 standard, with longer mags and longer COAL. If I were considering this route, I think I would have made it long enough to use some of the longer .277 bullets, without giving up powder space. 2.30 doesn't gain enough space to justify a whole new magwell and specification, at least not to me.

But...I don't own a 6.8 yet, so maybe they have their reasons!

They are going to have to find someone who will shepherd this through SAAMI as a completely new cartridge, I'm thinking.

stanc

04-07-2012, 09:12 PM

2.30 doesn't gain enough space to justify a whole new magwell and specification...
That's true. But, the reason for the new mag well is the need to accommodate a P-Mag designed for the fatter 6.8 SPC cartridge case. While they were at it, they took the opportunity to increase length enough so that SPC II ammo (such as offered by Wilson Combat) could also be used.

Being able to use 2.30" loads is just a nice "plus" that could be incorporated with minimal effort and expense. To go longer would entail a much more extensive redesign of both upper and lower receiver assemblies, resulting in an "AR-12.5" platform.

Variable

04-08-2012, 12:05 AM

Meh, maybe they got somebody to bite. It wouldn't be the first time if they got stood up for the dance though. Guess we'll have to wait and see.

LRRPF52

04-08-2012, 12:53 AM

Jordanian Secret Service has purchased 6.8 SPC PDW's from LWRC, and there is a totally different lower/upper receiver set on that PDW. The Middle Eastern nations with minority rulers buy all kinds of crazy weapon systems from different countries all the time. It's like a sampling of arms from around the world. You'll see various rifles from H&K, Steyr, the US, former Warsaw Pact, Israel, South Africa, FN, etc.

Their logistics would be a nightmare if they had any. Most of their aviation is maintained by US contractors working for big money after a term or two in the Air Force or Army, or working for one of the aircraft manufacturers/subcomponent manufacturers.

To infer that the 6.8 is gaining widespread military adoption because of the Beduin King's body guard service in Jordan is a bit of a stretch. The Grendel will do everything that the 6.8 will do, even from short barrels, so between the two cartridges for consideration for military use, the Grendel makes way more sense. I still don't see a huge need for anything other than a 5.56 in a PDW though, unless you go below a 10.25" barrel length, which is an extremely small niche market anyway. 10", 11.5", and 12.5" 5.56 carbines generate plenty of velocity, despite what all the claims have been.

There is zero reason to deviate from 5.56 in a carbine for military use. The biggest demand is in quality range time, which is not currently supported by most of the military. Allocation of range and ammo resources, compounded with a lack of institutional prioritization of true practical marksmanship are the main issues. Adoption of a new caliber for carbines would only exacerbate the current situation.

Schwag173

04-08-2012, 01:44 AM

Variable

04-08-2012, 04:18 AM

I still don't see a huge need for anything other than a 5.56 in a PDW though, unless you go below a 10.25" barrel length, which is an extremely small niche market anyway. 10", 11.5", and 12.5" 5.56 carbines generate plenty of velocity, despite what all the claims have been.

I don't keep up with the 5.56 much anymore since we just use whatever we're given at work, but what is the best general purpose "serious" ammo these days? I still have Mk262 Mod 1 for my personal 6933, but we don't get issued it and I don't have much left.

Schwag173

04-08-2012, 04:29 PM

A subjective example, but a lifelong friend is a career Army officer that related a conversation he had with another officer about a year ago. The second guy headed up what is essentially the Army's 'future small-arms' office. According to my friend, the head honcho was "not even a 'gun-guy'," and expressed that the Army has zero interest in a new cartridge. With the draw-down of our overseas deployments and with the crappy economy, I (sadly) foresee that Uncle Sam will continue as before.

Here's an article about the new carbine being sought. No mention of a new cartridge. I wish it were different; I'd love to see something like an HK416 in 6.5 Grendel adopted.

http://www.military.com/news/article/gun-firms-fear-army-carbine-fait-accompli.html

bwaites

04-08-2012, 05:11 PM

Schwag, have you played much with the HK416? I've seen and handled them several times. While the idea seems great, the actual shooting experience was very disappointing according to friends whom I trust in such things.

I thought the ergonomics were inferior to the AR, with the weight in the wrong places.

Truthfully, I still haven't found one of the new rifles that I think is a real step forward in the race. Some of them have some interesting features, but they all have drawbacks that take them out of the running as far as I am concerned. (That doesn't mean I don't want them, it just means I don't seen them as a real step forward!)

The AR is so modifiable, that you can make one that will just about be perfect for what you may want. The new rifles, not so much. I think its because they are designed by committee, and thus are a series of compromises. When you look at the great military rifles of the past 100 years, most are basically one man designs....the Garand, the AR, the Kalashnikov, etc.

Tony Williams

04-09-2012, 12:57 AM

LRRPF52

04-09-2012, 03:41 PM

I don't keep up with the 5.56 much anymore since we just use whatever we're given at work, but what is the best general purpose "serious" ammo these days? I still have Mk262 Mod 1 for my personal 6933, but we don't get issued it and I don't have much left.

If only 2-legged dogs are to be shot, M193 works awesome. If a certain level of barrier penetration is desired, M855 is not a bad round, and still has excellent wound ballistics since it has a thin jacket as well. Wolf has very thick jackets, and is lower-powered, so it is not a good wound-producer. Many of the civilian 55gr bullets don't have thin jackets, so who knows how they would perform.

Within 150yds, I like bullets like the M193 and M855, or the LE Winchester SXT's, ballistic tips, and bullets designed to come apart. The 77gr SMK's and Scenars are good for distance work, and making an SBR run more reliably due to the bering surface and weight providing more resistance, and consequently more back-pressure for the gas circuit.

LRRPF52

04-09-2012, 03:53 PM

Here's an article about the new carbine being sought. No mention of a new cartridge. I wish it were different; I'd love to see something like an HK416 in 6.5 Grendel adopted.

http://www.military.com/news/article/gun-firms-fear-army-carbine-fait-accompli.html

I can't stand the HK416. It handles horribly compared to a DI M4, even when suppressed. The M4A1 SOMPOD Block II is the way to go, in 5.56 NATO. The main improvements that the M4 needs is removal of that Gypsy witch doctor abortion 3rd BURST mechanism, and installation of a polished A1 trigger and hammer FCG, followed by a mid-length or rifle-length free-float handguard, plus FDE Cerakote finish on all the metal parts. This is what SOCOM is doing already (SOCOM always had M4A1's with the A1 trigger mechanism). Free-floating helps with heat dissipation, no loss of zero with accessories, weapon longevity since dynamic tension on the handguard no longer induces stress on the barrel extension with high temps, and of course, accuracy.

The caliber needs to stay the same. 5.56 is an awesome cartridge for the Rifleman, Grenadier, Fire Team Leader, Squad Leader, RTO, PL, Scout/Observer, Designated Marksman with 77gr Mk262, Ammo Bearer, Assistant Machine-Gunner, Forward Observer, Combat Medic, Assaulter, Combat Engineer, and any other dismounted duty position frequently placed in the realm of Light Infantry engagements. Any suggestion that these duty positions should be sapped with heavier and less ammunition would not be met well with the troops, and would reduce the number of bounding overwatch cycles that a dismounted unit could conduct before needing to be re-supplied or relieved after reaching critically-low ammunition loads.

txgunner00

04-09-2012, 07:18 PM

... The main improvements that the M4 needs is removal of that Gypsy witch doctor abortion 3rd BURST mechanism, and installation of a polished A1 trigger and hammer FCG, f...

LOL. That's a good way to describe it. I agree.

LRRPF52

04-09-2012, 08:53 PM

The Army has already started removing the 3rd BURST mechs and installing AUTO triggers. Whoever instituted the 3rd BURST mechanims on the M16A2 needs to be flogged with rusty MILES gear harnesses.

txgunner00

04-09-2012, 10:08 PM

MILES. yuck :p

Those engineers should be thrown to the dogs.

LRRPF52

04-09-2012, 11:02 PM

Back to the new MultiRole LMG concept. It has been mentioned in this thread that a 130gr Solid has already been made, namely the Barnes 130gr. They have also come out with a Barnes 127gr LRX long-range hunting bullet. There are no practical limitations on a "green" projectile of already-in-use bullet lengths that are viable in the Grendel.

There is also a new member here chambering a 1919A4 Browning in Grendel, and is using disintegrating links made of nylon:

http://www.65grendel.com/forum/showthread.php?2552-1919a4-belt-fed-Grendel&p=27594#post27594

I was thinking you could take existing M27 links and run them through an expander mandrel after heating them, so they open up to the Grendel case body for a prototype LMG.

I can't wait to see the actual constant recoil principle LMG spitting 130-140gr Grendel loads out next to a 7.62 GPMG, and beating it for wind deflection and penetration. This is a vision I've had for years.

stanc

04-10-2012, 01:31 AM

Jordanian Secret Service has purchased 6.8 SPC PDW's from LWRC, and there is a totally different lower/upper receiver set on that PDW.

To infer that the 6.8 is gaining widespread military adoption because of the Beduin King's body guard service in Jordan is a bit of a stretch.

There is zero reason to deviate from 5.56 in a carbine for military use. The biggest demand is in quality range time, which is not currently supported by most of the military. Adoption of a new caliber for carbines would only exacerbate the current situation.
I don't see 6.8 being adopted by any organization in the DOD. Even SOCOM, I'm sure, would stick with 5.56, if only for logistical reasons.

If any entity is actually planning to adopt 6.8, as the LWRC guys have intimated, I'd bet it's the Coast Guard. The USCG previously demonstrated independence in such matters by adopting .40 S&W for their standard pistol caliber. They may well be planning to do so again for their rifle cartridge.

Back to the new MultiRole LMG concept. It has been mentioned in this thread that a 130gr Solid has already been made, namely the Barnes 130gr. They have also come out with a Barnes 127gr LRX long-range hunting bullet. There are no practical limitations on a "green" projectile of already-in-use bullet lengths that are viable in the Grendel.
Forgive me, but I remain skeptical. The 130gr TSX is 100% copper, while "green" military ball projectiles with steel/copper or steel/steel cores would be significantly lighter. The same is true of conventional steel-core w/lead sheath construction, as shown by the Swedish AP bullet, which weighs a tad more than 110gr.

If you want me to buy into the idea of 130-140gr "green" or steel core, military ball, you'll have to provide much better evidence.

There is also a new member here chambering a 1919A4 Browning in Grendel, and is using disintegrating links made of nylon:

http://www.65grendel.com/forum/showthread.php?2552-1919a4-belt-fed-Grendel&p=27594#post27594
Yeah, that looks interesting.

I was thinking you could take existing M27 links and run them through an expander mandrel after heating them, so they open up to the Grendel case body for a prototype LMG.
So try it and let us know if it works.

I can't wait to see the actual constant recoil principle LMG spitting 130-140gr Grendel loads out next to a 7.62 GPMG, and beating it for wind deflection and penetration. This is a vision I've had for years.
I'd like to see it, too. :cool:

Schwag173

04-10-2012, 01:37 AM

Schwag, have you played much with the HK416? I've seen and handled them several times. While the idea seems great, the actual shooting experience was very disappointing according to friends whom I trust in such things.

Admittedly, no. That's why I was careful to add the word "like." I can see why, in military circles, a piston-AR would viewed as an improvement over the DI design. I'm with you on the wonderful balance and handling qualities of the original.

My aforementioned friend said it best; "The average Joe (grunt) just wants a rifle that will go bang every time he pulls the trigger. Instead, the Army keeps searching (in vain) for the ultra-space-age technological masterpiece."

LRRPF52

04-10-2012, 06:31 PM

Admittedly, no. That's why I was careful to add the word "like." I can see why, in military circles, a piston-AR would viewed as an improvement over the DI design. I'm with you on the wonderful balance and handling qualities of the original.

My aforementioned friend said it best; "The average Joe (grunt) just wants a rifle that will go bang every time he pulls the trigger. Instead, the Army keeps searching (in vain) for the ultra-space-age technological masterpiece."

The funny thing is that one of the biggest factors in reliability with the AR15 family of weapons lies right in the soldier's hands and individual control: proper lubrication. The military and industry has already provided him with an extremely reliable weapon, with great ammunition and reliable magazines. If he would just keep the bolt carrier wet, it will run like a champ-better than AK's and other assault rifles, in my experience.

Schwag173

04-11-2012, 02:10 AM

The funny thing is that one of the biggest factors in reliability with the AR15 family of weapons lies right in the soldier's hands and individual control: proper lubrication. The military and industry has already provided him with an extremely reliable weapon, with great ammunition and reliable magazines. If he would just keep the bolt carrier wet, it will run like a champ-better than AK's and other assault rifles, in my experience.

Personally, I agree that DI is fine the way it is. But ... there's that rare scenario now and again so I at least tolerate the (military) interest in piston guns. I own nothing but DI and have had many a debate with a co-worker that is excessively proud of his piston guns. I got that former Marine to bow his head in admission that he never had a DI gun stoppage the entire time he was in the Corps. Had him on that one. :)

LRRPF52

04-11-2012, 03:37 AM

There's a lot to be said for a design that keeps all the moving parts isolated from external debris as much as practically possible. Once you locate critical components outside and exposed to fine & large sand particles, you're asking for the system to cough. Not to say that the DI system won't choke in the worst of conditions, but I feel that it prolongs the inevitable more than an op-rod driven gun.

Out of 10 years in the Army spending most of that time either in the field or forward-deployed, I had very few malfs with my issued M16A1's, M16A2's, M4's, and M4A1's. The very few malfs that I did have involved one of these scenarios:

1) A 30rd magazine that was so old, the aluminum had turned orange, with the spine splitting and feed lips all jacked up
2) No lubrication on a recently command inspection-stripped dry M4
3) Mega dust storm where the weather front covered an area spanning from Eastern Turkey to Northeastern Egypt, and swept eastward through the Levant, Mesopotamia, and Arabian Peninsula like a massive hurricane that hits the Eastern US Seaboard-only with dust replacing the rain. Not even our M24's or breacher shotguns could chamber a round in that environment, so good luck with any self-loader.

txgunner00

04-11-2012, 02:00 PM

Same here on causes of malfunctions in my experience. 90% magazine related, 9% lubrication related, 1% other.

Maybe in the future piston will be the way to go but there are presently too many unknowns for my taste.

stanc

04-11-2012, 05:00 PM

Back to the new MultiRole LMG concept.

I was thinking you could take existing M27 links and run them through an expander mandrel after heating them, so they open up to the Grendel case body for a prototype LMG.
I just remembered something. You may wish to check with Bill A about that idea. Perhaps 6-8 years ago, he posted a photo of a few rounds of 6.5 Grendel belted together in M27 links. He never said if he altered the links to increase the loop diameter, or if he just forced the rounds in.

But, the question isn't if the 6.5 round can fit into such a link. That's already been demonstrated. Bill A did it with 5.56mm M27 links, and I did it with 6mm SAW links (which I recently gave to Bill W), which are identical to M27 links except for larger loop diameter and longer indexing tabs.

The real issue is compatibility with the feed mechanism. With 5.56, the front feed pawl pushes against the cartridge shoulder, and the cartridge stop also engages the shoulder. With 6.5, there appears to be too little case shoulder ahead of the link for that to work. See attached photo.

LRRPF52

04-11-2012, 10:24 PM

I was thinking about the same thing when looking at the Grendel case and the longer shoulder position of the 5.56 NATO case, especially when considering the feed pawls. The question isn't about getting the cartridge aligned properly, but if there is enough traction in the feed mechanism to purchase the cartridge on enough surface area to pull the Grendel cases through the feed mechanism.

Thinking back on the underside of the feed tray cover, where the heart of the belt-fed system lies, there are 2 feed pawls IIRC. One pulls the area ahead of the link, and one pulls on the base of the cartidge. Your point makes a lot more sense now, as I was thinking that you were saying that a Grendel link couldn't be made based on loop diameter or something.

One possible solution to this could be having the forward feed pawl a little longer and contoured so that it pulls the cartridge neck. That would be an easy solution, as long as it doesn't interfere with the ability to strip the cartridge from the links and drive it forward into the feed ramp that's on the bottom of the feed tray.

http://i1085.photobucket.com/albums/j422/LRRPF52/FeedTrayMechanism.gif

LRRPF52

04-12-2012, 03:21 PM

Another thing about the manner in which the feed tray mechanism cycles is that when the bolt carrier group drives forward, the cam rides inside of the curved arm that moves the feed pawls, which are under spring tension so they can ride over the cartridge and purchase the next one.

After the fired cartridge's gas begins to operate the action, the op-rod and bolt carrier move rearward, which drives the cam back in the track to pull the next cartidge into the feed slot on the feed tray, so it looks like the mechanism would likely function even without modification using the Grendel case. The main issue that might come into a play is a completely new feed tray cover with a higher clearance for the larger cases, but using the same subcomponents.

txgunner00

04-12-2012, 03:48 PM

I would think it could be done without too much modification. Maybe a different feed tray (or just the stop) to fit the profile of the Grendel case and different pawls, possibly just the front pawl can grab the neck instead of the case body.

stanc

04-12-2012, 08:24 PM

On the old forum, somebody else suggested having the front feed pawl push against the case neck. I don't know whether or not that's a viable option, but I've never heard of any machine gun that does it.

Back in 2006, a gunsmith friend took some measurements on an M249. The front and rear feed pawls are 0.241" in width, with spacing as shown on the attached picture.

The feed tray would require a new cartridge stop, reconfigured as shown. The left side of the stop would need to be shifted ~0.03" to the right to allow for correct alignment of the fatter cartridge with the feed slot. And note that even changing the lower left from a 45-degree bevel to a 90-degree corner, contact with the case shoulder looks rather iffy.

stanc

04-13-2012, 07:52 AM

I was browsing Tony Williams' forum tonight. They, too, have had endless discussions/debates about designing a cartridge that could replace 7.62 NATO. Apparently they've settled on what they call a 6.5/8/800 (6.5mm 8-gram bullet @ 800 m/sec).

One member suggests using an AR-10 in 6.5 Creedmore as a proof-of-concept demonstrator.

...to quickly evaluate the 6.5/8/800 concept from an assault rifle, then an AR10 clone with a 16" bbl like the L129 (with select fire option) chambered in 6.5mm Creedmoor might be a good start IMO.

http://forums.delphiforums.com/autogun/messages?msg=5041.3

...a quick and cheap capability demonstrator one could use to help prove and sell the concept of 6.5/8/800 from a performance standpoint. It would demonstrate the superior exterior ballistics, demonstrate terminal ballistics, and demonstrate controllability of such a cartridge.

It would also be easy to convert a Mk48 LMG over to 6.5mm Creedmoor or 6.5x47mm Lapua to demonstrate the capability of the 6.5/8/800 concept to replace 7.62mm NATO in the machinegun role.

I may be wrong but I think the military brass may need to be sold on the need for, and the capabilities of, a 6.5/8/800 type cartridge before they can be sold an actual idealized 6.5/8/800 cartridge.

http://forums.delphiforums.com/autogun/messages?msg=5041.5
Unfortunately, nobody seems interested in getting a gun and actually shooting it to see if reality matches their theory. :(

http://www.paradata.org.uk/files/imagecache/profile/files/pictures/16x-2011-tfh-003-303.jpg

Another thread of possible interest:

I have been involved in a fairly lengthy industry discussion about medium caliber military cartridges. Now that everyone has access to basic ballistic calculators, there is some doubt about whether our ideal 6.5 mm to 7 mm cartridge would offer a significant enough weight saving versus 7.62 mm to justify adoption. In order to achieve a flat trajectory and to match 7.62 mm at 1,000 metres, it is argued that we would need a cartridge that's quite close to the M80 in size, volume and weight.

Cris Murray's 6.86 mm UIAC is an example of the problem: clearly a very good cartridge. But the weight saving isn't even 10%.

http://forums.delphiforums.com/autogun/messages?msg=5023.1

LRRPF52

04-13-2012, 03:20 PM

They have correctly identified one of the problems with the 7.62 NATO-based cartridges: Weight/size

I want to get rid of the whole T65/M80 case because of the weight/size penalty it brings with it. It also is not a good case for a high-volume military weapon for a 6.5mm because of over-bore and throat erosion, although some of that can be dealt with using modern metallurgy.

This further steers us to the shorter .445" case head diameter, made of strong brass capable of higher pressures, with a shorter overall length. We don't need a case volume of 44-50grs to beat the 7.62 NATO when pushing 6.5mm bullets either.

I really think a 130gr Grendel is the way to go.

stanc

05-15-2012, 02:06 AM

I'm not sure how significant this is, but note the calibers:

SWEAT Course (Soldier Weapon, Equipment, and Test)
Sponsored By JSSAP

Page 15

Determine the Ballistics Protection/Bullet Traps for Each Station
•
Ballistic protection plan designed to preserve overall lifetime of course and keep a low total of cost ownership
•
Design Considerations
•
Create safe and realistic environment
•
Ammunition
•
9mm
•
5.56 (M855A1 in Phase II)
•
5.7mm
•
6.5mm
•
6.8mm
•
7.62
•
Maintenance life-cycle cost
•
Durability

http://www.dtic.mil/ndia/2011smallarms/Thursday12791Wilson.pdf

Tony Williams

06-10-2012, 04:42 AM

I've been photoshopping again :cool:

Some thoughts on the options for a GPC (General Purpose Cartridge) which could replace the 7.62x51 in portable small arms carried by dismounted infantry with substantial reductions in weight and recoil (and could also replace the 5.56mm in the infantry squad, although that would stick around for a long time in non-infantry applications).

I start with the assumption that the ideal GPC cannot be accommodated in the AR-15 platform. The Grendel is by far the best attempt to do so but, as is being discussed on another thread on this forum, the case width limits the maximum safe pressure to around 50,000 psi, which I suspect isn't quite enough to extract the performance required to replace the 7.62mm. Particularly when the US Army's preference for lead-free bullets is taken into account (longer bullets = less room for propellant). So all of the proposals below exceed the overall length of the 5.56x45.

The first three on the left are based on the 6.8mm Rem only with the case extended slightly to 45mm and (more importantly) the overall length allowed to grow a lot more to use higher-BC bullets. The three versions show 6.35mm, 6.5mm and 6.8mm calibres. These were chosen because the ARDEC calibre survey tested cartridges in 6.35mm and 6.8mm (but not 6.5mm) and concluded that these two were both better than 5.56mm, 6mm or 7.62mm.

The next three (in the same calibres) are based on the Grendel, only with the case extended to 42mm. The longer OAL would ensure that they could not be chambered in modified AR-15 actions, so could be loaded to higher pressures. Maybe this could be designated something like 6.5GM (Grendel Maximum)? With the increasing availability of commercial rifles based on the AR-10 action, this could find plenty of good homes as a big brother to the Grendel (and being a bullpup supporter, I'd love to see one of these in a Kel-Tec RFB!). There is obviously room to extend the OAL to accommodate lead-free bullets. The aim would be to match the performance of the 6.5 Grendel in 24 inch barrels (in metric round figures, 8g at 800m/s, or 123 grains at 2,620 fps) only with longer, lead-free bullets in shorter barrels (20 inch, with decent performance maintained from carbine barrels).

The final cartridge is the 7.62x51 for comparison.

The cartridges shown in the pic are purely indicative and the designs would doubtless be amended by people who know more about the technicalities than I do.

Comments?

http://www.quarry.nildram.co.uk/GPC.jpg

JASmith

06-10-2012, 05:19 AM

...the case width limits the maximum safe pressure to around 50,000 psi, which I suspect isn't quite enough to extract the performance required to replace the 7.62mm. Particularly when the US Army's preference for lead-free bullets is taken into account (longer bullets = less room for propellant). So all of the proposals below exceed the overall length of the 5.56x45...
I like the photos!

There seems to be continuing confusion, however, about the pressure limitations of the Grendel cartridge.

Per Bill Alexander, the base width indeed places more thrust on the AR15 bolt, which results in reduced average bolt life when run at pressures significantly above 50,000 psi. This is a reliability issue unique to the AR15 bolt.

Also, Bill indicates that Grendel case itself can readily handle upwards of 58000 psi (http://www.65grendel.com/forum/showthread.php?2839-Grendel-ballistics-overstated&p=34126&viewfull=1#post34126).

These pressures are safe in appropriate actions. When coupled with a longer COAL as suggested, then the desired velocities and bullet weights for supplanting the 7.62X51 M80 cartridge are likely attainable.

Tony Williams

06-10-2012, 05:47 AM

I think that to have one cartridge in two versions, differing only in the length of the bullet protrusion and the chamber pressure, would be confusing. We don't want to get into a 6.8mm Rem situation, with two different chambers!

If we're no longer limited to 5.56mm action lengths, then IMO it's better to produce a slightly different case, extending it a bit to make sure that it can still deliver the required performance from 20 inch barrels when loaded with lead-free bullets (especially the even longer tracer versions). That might also mean that it needn't be loaded to maximum pressure to start with, which is no bad thing.

Edit to add: a little extra capacity would also make it easier in due course to produce a polymer cased (with metal base) version, since these tend to have thicker walls. These cases are improving all the time, and offer big weight savings - important for the military.

stanc

06-10-2012, 06:07 AM

Some thoughts on the options for a GPC (General Purpose Cartridge) which could replace the 7.62x51 in portable small arms carried by dismounted infantry with substantial reductions in weight and recoil (and could also replace the 5.56mm in the infantry squad, although that would stick around for a long time in non-infantry applications).

I start with the assumption that the ideal GPC cannot be accommodated in the AR-15 platform.

The three versions show 6.35mm, 6.5mm and 6.8mm calibres. These were chosen because the ARDEC calibre survey tested cartridges in 6.35mm and 6.8mm (but not 6.5mm) and concluded that these two were both better than 5.56mm, 6mm or 7.62mm.

There is obviously room to extend the OAL to accommodate lead-free bullets.

Comments?
Looks good. Ought to work.

The 0.42" case offers a slight advantage to machine gun belt length (for 100 linked rounds).

The 0.44" case gives a small advantage to rifle magazine ergonomics (front-to-rear dimension).

No significant weight difference between the two case options. Probably no significant difference in muzzle velocities, either.

Major drawback to both is the non-availability of platforms optimized for intermediate-length, intermediate-diameter cartridges, which means it'd be necessary to use the bulkier, heavier weapons developed for 7.62x51 (such as the AR-10, Mk17, etc).

Tony Williams

06-10-2012, 06:47 AM

Major drawback to both is the non-availability of platforms optimized for intermediate-length, intermediate-diameter cartridges, which means it'd be necessary to use the bulkier, heavier weapons developed for 7.62x51 (such as the AR-10, Mk17, etc).

True, development and initial use would be in AR-10 sized actions (although these could maybe be lightened a bit). But if such a round were ever adopted by the military, intermediate sized actions would appear...

stanc

06-10-2012, 07:54 AM

True, development and initial use would be in AR-10 sized actions (although these could maybe be lightened a bit).
How can that be done?

JASmith

06-10-2012, 01:56 PM

I think that to have one cartridge in two versions, differing only in the length of the bullet protrusion and the chamber pressure, would be confusing. We don't want to get into a 6.8mm Rem situation, with two different chambers! ...
I understand the logic, but there is also the logic of the enormous investment needed to qualify a new cartridge. The 6.8 and the Grendel have both gone through the process. The Grendel even has steel cases in the pipeline.

I've done the math, and adding, say .05" to the body length adds only a grain or two to the case capacity. This is somewhat less than the 3+ grains one gets by merely seating a COAL of 2.4" to 2.5" with no other change to the cartridge. The case remains the same.

I've also looked at scaled drawings of the longer case -- there won't be any confusion between the two because one will have a conventional appearance and the other will have the tip of the bullet sticking waay out there!

Having said the above, I would concur that, should the investment be available (a truly huge IF!), then the most attractive options would boil down to lengthened versions of either the 6.8 or the Grendel, both in 6.5 caliber.

The fatter case of the Grendel-based option would likely be more weight efficient because the wall thicknesses tend to remain about the same, so the case weight in that area goes with the radius, while the volume of the interior goes with the square of the radius.

LRRPF52

06-10-2012, 04:12 PM

We would be able to achieve all that we wanted for a "beat 7.62 M80 ball" using a 2.300" COAL and 130gr bullets in the Grendel, launched from a dedicated platform built around the cartridge. There is zero need to develop a new case, when we look at the pressure capacity that the Grendel brass can sustain. We also don't have to ramp the pressure up too crazy, due to the efficiency of 6.5mm projectiles.

stanc

06-10-2012, 08:44 PM

We would be able to achieve all that we wanted for a "beat 7.62 M80 ball" using a 2.300" COAL and 130gr bullets in the Grendel...
Question is, can that level of performance be achieved with lighter (110-115gr), lead-free bullets?

Variable

06-11-2012, 03:19 AM

Well, if you guys are talking about all new stuff:

1.) Use a new slightly larger magwell like LWRC was/is going to make.

2.) Develop a new uber polymer mag for said magwell.

3.) Use a beefier barrel extension with a larger bolt for higher acceptable pressures.

4.) Stick a fork in it and call it done.

Didn't the .222 spawn the eventual 5.56 cartridge?

The Grendel could spawn a slightly zippier .308 killer if called upon I guess. You'd hear whining from all of us folks with Grendels, but they'd sell even more rifles as we quietly stood in line for backorders on the new "_______"(insert roided Grendel Max cartridge's name here).

We love how the Grendel fits in the AR platform now, but most people eventually buy or build a whole 'nother rifle anyway.

Platform difference:

New upper, barrel extension, bolt, bolt carrier, lower receiver, and magazines.

You could still keep a lot of AR parts, and if somebody like Magpul made the mags then people would fight over who got the first shipment of them....

The first write up in a magazine showing how an 18" carbine performed at 1000 yards would incite a stampede of folk trying to get their hands on the new 6.5 "Death Wand".LOL:D

Tony Williams

06-11-2012, 04:33 PM

How can that be done?

The guns taking part in the current US Army carbine competition have to meet a tight weight limit (7 lbs or so) and have been pared down as a result. I have examined and handled the HK candidate, and although based on the HK 416 it is significantly lighter.

I presume therefore that current 7.62mm weapons could be similarly pared down, especially to handle a smaller and less powerful cartridge.

stanc

06-11-2012, 07:46 PM

I don't know if that presumption is warranted. At least, I don't see where any weight can be trimmed from a design that's already rather lean.

Tony Williams

06-12-2012, 05:22 AM

Let me put it this way: I have little doubt that the HK417 could be pared down in the same way as the HK416.

The FN MK17 may be less easy to change, but there's hardly any need because it's so light anyway (not much heavier than the MK16).

LRRPF52

06-13-2012, 03:21 PM

You can make an AR10 as light as a SCAR-17 by simply using a pencil barrel and lighter COTS components.

If someone showed up to the competition with a DMR system that was adaptable to both 5.56 and Grendel, and they demonstrated what a Grendel could do versus a 7.62 NATO carbine at distance, that could be an eye-opener, especially when considering soldier's load and the ability to sustain the fight longer than 7.62 NATO, with less recoil, and better terminal ballistics.

If I were selling it, I would say,

"Look, 7.62 NATO will be around for a long time, and there is no need to get rid of it in aircraft and vehcile-mounted, mechanically-fired weapons. However, I think we're really at a stage where we can seriously meet some of these constant weight-reduction requirements for the dismounted soldier, by displacing belt-fed 7.62 GPMG's, and DMR's, with a more capable cartidge, in a lighter system. Watch what it does across the target array on this range...."

JASmith

06-13-2012, 04:04 PM

Well said!!!

stanc

06-13-2012, 10:12 PM

You can make an AR10 as light as a SCAR-17 by simply using a pencil barrel and lighter COTS components.
Yes, but that would not be representative of the weight when configured for military use.

For instance, the SR25 EMC weighs 8.3 lbs.

http://autoweapons.com/photos10/may/kacemcarbinei.jpg

If someone showed up to the competition with a DMR system that was adaptable to both 5.56 and Grendel, and they demonstrated what a Grendel could do versus a 7.62 NATO carbine at distance, that could be an eye-opener, especially when considering soldier's load and the ability to sustain the fight longer than 7.62 NATO, with less recoil, and better terminal ballistics.

If I were selling it, I would say,

"...I think we're really at a stage where we can seriously meet some of these constant weight-reduction requirements for the dismounted soldier, by displacing belt-fed 7.62 GPMG's, and DMR's, with a more capable cartidge, in a lighter system. Watch what it does across the target array on this range...."
I wholeheartedly agree the concept needs to be demonstrated.

The question is, which approach would give best overall results?

a. Your's - 5.56 NATO for carbine, 6.5 Super G for LMG, DMR.

b. John's - 6.5 Grendel for carbine, LMG, DMR.

c. Tony's - 6.35/6.5/6.8 GPC for rifle, GPMG, DMR.

Variable

06-13-2012, 10:34 PM

Yes, but that would not be representative of the weight when configured for military use.

For instance, the SR25 EMC weighs 8.3 lbs.

http://autoweapons.com/photos10/may/kacemcarbinei.jpg

I wholeheartedly agree the concept needs to be demonstrated.

The question is, which approach would give best overall results?

a. Your's - 5.56 NATO for carbine, 6.5 Super G for LMG, DMR.

b. John's - 6.5 Grendel for carbine, LMG, DMR.

c. Tony's - 6.35/6.5/6.8 GPC for rifle, GPMG, DMR.Without a wealthy backer with cnc machines, my vote would be "B". Super Grendel would probably be best, but what doesn't exist can't be demonstrated.

Everything is a series of compromises in one form or another, and while I'd like to see a "Super Grendel", I think the current form is sufficient for use across the board.

ETA: I should say that what LRRPF52 said about 5.56 for carbines is spot on. But considering what kind of enviro hoops they are probably going to put the 5.56 ammo through--- I'd just say the heck with it and go Grendel to retain lethality. From a logistics standpoint it would be rather advantageous for one cartridge to cover it all. I'd be willing to take the hit on overall loadout quantity in exchange for increased lethality and penetration from short barrels at various ranges, not just up close.

LRRPF52

06-13-2012, 10:37 PM

The SR25 EMC doesn't have the extreme lightweight barrel profile that the SCAR does, and has more 1913 real estate that makes up for more weight than the SCAR carbine-length receiver, which is being lengthened for the SCAR Sniper Support Weapon in at least the 5.56 version. They're not going to get any groups wothwhile in a lightweight SCAR barrel for the SSR, but it does offer a nice heavy-hitting carbine with the -17 for general purpose use augmenting the majority of guys carrying 5.56 carbines.

They could have a lighter gun, with a heavier profile barrel that will provide both the increased terminal energy, and accuracy of a DMR in one shebang with a Grendel DMR, plus not lose any significant effectiveness as a general purpose infantry rifle in the 50m-500m fight.

Combining the introduction of a Grendel LMG, DMR, and the .338 NM MMG could offer the systemic 1-2-3 punch that would be needed to convince the long-term strategists, logisticians, and commanders that we're finally ready to begin the necessary steps to sending 7.62 NATO into its final phase-out schedule, as modular systems like the Mk48 are upgraded with a Grendel Conversion kit, so units can burn the crap out of some 7.62 in training, then phase in Grendel and the .338 MMG powerhouse. With the addition of lightweight, precision-guided, man-portable, indirect-fire systems, the following force structure begins to emerge:

Light Weapons:
Grendel LMG
Grendel DMR

Heavy Weapons:
.338 MMG
LMPPGIFS (Lightweight Mortar w/precision warhead array)

stanc

06-14-2012, 02:40 AM

From a logistics standpoint it would be rather advantageous for one cartridge to cover it all. I'd be willing to take the hit on overall loadout quantity in exchange for increased lethality and penetration from short barrels at various ranges, not just up close.
Those arguments are also put forth for the 6.X GPC (and Murray's 7 UIAC). The main difference is in the size and weight of the weapons. The GPC/UIAC require guns as big and heavy as for 7.62 NATO, whereas Grendel fits the smaller, lighter firearms made for 5.56 NATO.

Both of the above would completely replace one NATO cartridge (5.56), and so may be a better fit to the Army way than Paul's 6.5 Super Grendel, which would require adding a third caliber to the inventory alongside 5.56 and 7.62 NATO. From a purely technical standpoint, the Super G seems very attractive, but IMO it has the least chance of success. Plus, as you noted, one cannot demonstrate something that does not exist.

JASmith

06-14-2012, 03:56 AM

...6.5 Super Grendel, which would require adding a third caliber to the inventory alongside 5.56 and 7.62 NATO...
The "Super Grendel" would replace the 7.62x51 in dismounted infantry operations. He would dispose of the 7.62x51 in the following manner:

Originally posted by LRRPF52

If I were selling it, I would say,

"Look, 7.62 NATO will be around for a long time, and there is no need to get rid of it in aircraft and vehcile-mounted, mechanically-fired weapons. However, I think we're really at a stage where we can seriously meet some of these constant weight-reduction requirements for the dismounted soldier, by displacing belt-fed 7.62 GPMG's, and DMR's, with a more capable cartidge, in a lighter system. Watch what it does across the target array on this range...."
It would appear that his vision would result in a 2-caliber system for the dismounts.

stanc

06-14-2012, 05:05 AM

It would appear that his vision would result in a 2-caliber system for the dismounts.
His vision is for the operational use of two calibers by dismounted infantry.

But it would require adoption of a third rifle/machine gun caliber by the entire military force structure.

7.62 NATO will be around for a long time, and there is no need to get rid of it in aircraft and vehcile-mounted, mechanically-fired weapons.
- 5.56 NATO for carbines
- 6.5 Super G for LMGs and DMRs
- 7.62 NATO for vehicle and aircraft MMGs

I know of no historical precedent wherein the Army chose to add a new rifle caliber, without concurrently phasing out an old caliber.

However, there is historical precedent for refusing to adopt a third caliber: The 6mm SAW was proposed for a similar purpose as the 6.5 Super G, but rejected.

The other two concepts (6.5 Grendel, 6.X GPC) take the proven historical path, and would completely replace 5.56 NATO throughout the military.

LRRPF52

06-14-2012, 08:43 AM

Trying to replace 5.56 and 7.62 at the same time is probably too much of an adjustment for the entire NATO system to digest, and since there are more 5.56 NATO individual service weapons, therein lies the logistical quagmire. Using the Upgraded SAW and Mk48 platforms as transitional frames for the Grendel upgrade, while developing the DMR system, and replacing M240's with the .338 MMG is what I'm talking about.

7.62 NATO can be used as is needed while the new caliber is ramped up and absorbed into the various units.

They can also start looking at the .338 MMG to replace 7.62 and .50 BMG belt-fed weapons on vehicles & aircraft, since there would be a net weight-savings, with performance increase.

We also don't have to be held to the manner in which things have been done in the past, as so many processes have undergone radical changes in just the last 15 years, regarding military procurement, R&D, solicitations, end-user involvement in designs, and unit purchasing. It has largely been driven by the Special Operations community, which has a can-do attitude and posture, in contrast to the conventional military's "No, that violates this and that stack of regulations, blah blah blah..."

As SOCOM has shifted to the dominant, lead organization, rather than a supporting community for conventional forces, the tides of military planning and logistics have changed significantly. If you look at Desert Storm, SOF units were treated marginally. Those days are gone, and National Command Authority looks heavily on SOF units to bear the main effort of the majority of operations we currently are engaged in, not only in USCENTCOM, but USPACOM, USOUTHCOM, USAFRICOM, and USEUCOM.

As we ramp up in USPACOM to deter China from getting aggressive with Taiwan, the Philippines, friend-up to India, and maintain vigilance against North Korea, the conventional nature of force structure will pull the force back in the direction planners should have covered down on more, and trans-Pacific logistics will be a major issue in hauling material thousands of miles away.

They're re-opening Pubic Bay and Clark AFB in the Philippines, and China is not happy about that move, since some little commie witch state media anchor just declared that "It's an indisputable fact that the Philippines is part of soveriegn China, and always has been."

http://www.youtube.com/watch?v=KiudNjxTdg4

The Grendel LMG & .338 MMG support the lip service we've been hearing about a lighter, leaner, more efficient force for a long time, with actual platforms to execute it.

Variable

06-14-2012, 12:42 PM

They're re-opening Pubic Bay and Clark AFB in the Philippines, and China is not happy about that move, since some little commie witch state media anchor just declared that "It's an indisputable fact that the Philippines is part of soveriegn China, and always has been."

Sorry off topic: Holy smokes! Reopen Clark!!! OMGWTFBBQ!!! Why now??? After I'm married and too damn old to go back there??? I had more fun at Clark air base than I've ever had, or likely ever will have again in my entire life!!! I just can't begin to explain the level of awesome that resided at that place!!!

HaaaHaaahahahahahaha!!! I just searched the phrase "reopen clark air base" and this old article popped up:http://articles.orlandosentinel.com/1986-03-31/news/0210170032_1_bar-girls-subic-bay-pickets Oh but to have the women fight over us again!!!!!:D:D:D:D

Ok, maniacal rant in memory of lost youth over, back on topic. Sorry. Here is a more appropriate link about reopening bases in the Phillipines:http://thehill.com/blogs/defcon-hill/operations/231257-philippines-re-opens-military-bases-to-us-forces-

JASmith

06-14-2012, 01:54 PM

;) I hear you! Now, if they start reopening Thai bases, I would really be in trouble!! ;) :D

stanc

06-14-2012, 07:43 PM

Trying to replace 5.56 and 7.62 at the same time is probably too much of an adjustment for the entire NATO system to digest...
I'm not talking about replacing both 5.56 and 7.62 in the inventory, just 5.56.

...and since there are more 5.56 NATO individual service weapons, therein lies the logistical quagmire.
What quagmire? They managed to transition from the .30 M1 rifle to 7.62 M14, and from there to 5.56 M16, at a time when the armed forces were a lot bigger than now, so I think a switch could be handled now.

Using the Upgraded SAW and Mk48 platforms as transitional frames for the Grendel upgrade, while developing the DMR system, and replacing M240's with the .338 MMG is what I'm talking about.
Yes, I understood that. AFAIK, the .338 MMG is only a GD proposal, not something the Army is actively seeking to replace the M240.

The Grendel LMG & .338 MMG support the lip service we've been hearing about a lighter, leaner, more efficient force for a long time, with actual platforms to execute it.
That's what all of the alternative cartridges aim to do. But, none have yet demonstrated they can achieve it.

stanc

06-15-2012, 10:47 PM

A METHODOLOGY FOR SELECTING SMALL-ARMS ROUNDS TO MEET MILITARY REQUIREMENTS

http://www.cna.org/sites/default/files/research/0203070000.pdf

woohoo

06-16-2012, 03:52 PM

HANKA

06-16-2012, 07:33 PM

Stan, thanks for the Methodology PDF. Very interesting reading. To quote page 14: "Of the five basic calibers only the .264 caliber provides common round solutions."

Also interesting to see his strong emphasis on 50,000 psi being ideal for a military cartridge.

John

stanc

06-16-2012, 08:37 PM

Stan,
Just thought I would let you know Cris Murray is going to get his chance with the army and the 7x46 very soon.
He has AR10 carbines for testing now and some of the parts for the GPMG that he wants to replace the M240 with.
Heh, heh. Apparently you read the following post on 68forums:

http://68forums.com/forums/showthread.php?29635-7x46-UIAC-gets-a-chance&p=319057&viewfull=1#post319057

The article Harrison linked to is from April 2010 and says nothing about "a chance with the Army."

Last I heard from Cris Murray, he had converted an MG42 to 7x46 UIAC.

stanc

06-16-2012, 08:41 PM

Stan, thanks for the Methodology PDF. Very interesting reading. To quote page 14: "Of the five basic calibers only the .264 caliber provides common round solutions."
Yes, I knew you'd like that bit. :cool:

woohoo

06-17-2012, 01:14 AM

Heh, heh. Apparently you read the following post on 68forums:

http://68forums.com/forums/showthread.php?29635-7x46-UIAC-gets-a-chance&p=319057&viewfull=1#post319057

The article Harrison linked to is from April 2010 and says nothing about "a chance with the Army."

Last I heard from Cris Murray, he had converted an MG42 to 7x46 UIAC.
You mean they didn't send you a memo?
He has AR10s in 7x46, he was working on a MG42 and is working on his GPMG design.

http://68forums.com/forums/showthread.php?28608-Beefy!!&highlight=beefy

stanc

06-17-2012, 02:10 AM

You mean they didn't send you a memo?
Nah. I'm kept in the dark. I think I may be a mushroom. ;)

He has AR10s in 7x46, he was working on a MG42 and is working on his GPMG design.

http://68forums.com/forums/showthread.php?28608-Beefy!!&highlight=beefy
Hey, thanks for that link. Interesting developments.

stanc

09-01-2012, 06:00 PM

"...basically an extended Grendel case firing a 123 grain projectile."

http://forums.delphiforums.com/autogun/messages?msg=5242.142

Anybody have more info on this round, reportedly developed by the US Army Marksmanship Unit as their idea of a future infantry cartridge?

LRRPF52

09-01-2012, 10:22 PM

I'll be looking around for info on this as well. I'm not convinced that you really need a longer case, since we only need to load the COAL longer, with plenty of engagement surface in the Grendel case for the vast array of long projectiles, to have an ideal shoulder-neck junction placement of the projectile base, while allowing more powder without compression. A COAL of 2.400" would be nice, but we really need to know what projectiles we're dealing with and the expectations of those projectiles before determining the case dimensions.

The other thing I like about the Grendel from a long-term military logistics standpoint is that barrels don't burn out like 5.56 and 7.62 NATO. There is considerably longer throat and barrel life, even with the civvy-grade steels being used. Now imagine a hammer-forged, chrome-lined 4150 CMV barrel in military guns. LMG's could potentially be rated for longer cyclic, rapid, and sustained-fire round counts between barrel changes, and assault rifles would have longer-lasting barrels.

This is a very appealing combination for countries who are facing hard economic times, in addition to increasingly belligerent external threats within their region, like Eastern European nations.

Tony Williams

09-02-2012, 07:17 AM

I've been working on my web article on the case for a new general-purpose military rifle/MG cartridge, and have thoroughly revamped it: http://www.quarry.nildram.co.uk/The%20Next%20Generation.htm

HANKA

09-02-2012, 05:53 PM

Thanks, Tony, it's always good to read your thorough analyses. Your articles have been very influential in my thinking.

LRRPF52

09-04-2012, 04:43 AM

I just ran a series of data on how an Infantry Rifle Squad fare's with regards to combat endurance and follow-on mission capability after a chance contact while patrolling in the vicinity of a village.

With the successful execution of Battle Drill 1.a (Squad Attack), and NO casualties, the Infantry Squad is at 81% combat readiness after the quick pursuit of an enemy harassment team. 1-3 mags per soldier w/5.56 carbine were expended, with 100rds of linked per SAW, as well as 3x40mm HE per Grenadier.

They could endure one more engagement of this impact on their ammunition status, after which they would be 60% ready.

If I ran the sequence with Grendel, you need 2lbs more carrying capacity per Rifleman, Grenadier, Team Leader, and Squad Leader, for one less magazine. Not sure how much weight increase the SAW gunners would see.

8x30rd 5.56 NATO loaded aluminum mags = 8.47 lbs/240rds
7x30rd Polymer Grendel loaded mags = 10.5 lbs/210rds

You will never have the same bounds of fire & maneuver per weight with anything using projectiles that are significantly heavier than 5.56 NATO, so you have to convince Big Army that the increased strain on the logistics posture is really worth it in the long run, as re-supply operations slow down the pace of taking ground, while increasing combat arms AND combat support units, to include unit internal re-supply assets (Platoon Sergeant w/Medic, or 1SG w/driver, another Squad that could be combat-focused, etc.).

Tony Williams

09-04-2012, 01:18 PM

What does that tell us? That a Grendel round weighs more than a 5.56mm. Yep, knew that already. Using that assessment, the troops would have even more combat endurance if they were equipped with 5.7mm P90s or 4.6mm MP7s (all we need is a dinky little belt-fed MG to fire them).

Ammo weight is just one of the many considerations driving weapon and ammunition choices. By willingly carrying 7.62mm weapons instead of 5.56mm, the troops in Afghanistan have demonstrated that range and lethality can override weight in their priority order.

LR1955

09-04-2012, 02:55 PM

By willingly carrying 7.62mm weapons instead of 5.56mm, the troops in Afghanistan have demonstrated that range and lethality can override weight in their priority order.

Tony:

Joes tend to believe anything bigger must be better. Few if any have the skills to prove it. They see a bigger cartridge like a round of M-80 and think it is more effective than their round of 5.56.

What conventional forces have the option of carrying a 7.62 rifle over their issued M-4? I know there are EBRs and M-110's out there but they are not for general issue.

Please link us to a study that proves in quantitative (not qualitative) terms that hit and kill ratios in Afghanistan were significantly higher at distances from 300 to 600 meters because someone had a issued 7.62 carbine firing issued M-80 Ball as opposed to a 5.56 carbine firing issued M-855. And that the same study quantitatively proves that range overrides lethality and that range and lethality, range only, or lethality only override weight.

Just because someone carries a specific anything that is different from standard issue doesn't mean it is better.

LR1955

LRRPF52

09-04-2012, 02:57 PM

Ammo weight is just one of the many considerations driving weapon and ammunition choices. By willingly carrying 7.62mm weapons instead of 5.56mm, the troops in Afghanistan have demonstrated that range and lethality can override weight in their priority order.

They are issued a small arms structure that is a mix of mostly 5.56 carbines, with very few 7.62 DMR's. Nobody that I know of is carrying 7.62 NATO universally across their small arms mix, although the Norwegians did earlier in the campaign with the AG-3 before they adopted the HK416.

By this, we know that US/UK and other professional armies are not only willing, but in fact are employing a 2-caliber small arms mix at the Squad-level, when it used to be 5.56 NATO universal for at least a US Infantry Squad with M16 family and the SAW.

I still think a universal caliber at the Squad-level is doable with the Grendel, but not necessary, and I would still want an assault rifle load, versus the LMG load, which takes us back to our cost-benefit analysis to 5.56 NATO/MRLMG Grendel structure.

You are absolutely right about factoring in the performance capability of the cartridge/weapon system in relation to weight, and do we favor in the direction of:

* lightweight, higher mobility, longer combat endurance....or
* more weight, less mobility, less combat endurance, but higher-power ammunition

The current 5.56 NATO service weapon/7.62 DMR mix satisfies both of those considerations, without significantly reducing the unit's ability to make contact, fight through the contact, and be prepared for 2 more contact sequences before needing a re-supply.

The Grendel would reduce the weight of the 7.62 DMR, while increasing mag capacity and combat endurance of the Squad, and still allow the DMR's to perform as rifleman-assaulters within close quarters.

Tony Williams

09-05-2012, 01:01 AM

When it comes to ammunition weight, I suspect that belt-fed MGs are more significant than rifles. I recall hearing a US Army presentation a couple of years ago about the introduction of the MK48 7.62mm LMG. At that time, the dismounted troops were carrying both 5.56mm M249 and 7.62mm M240. The Army expected the troops to leave the M240 back at the base and take the MK48 instead - but they found that it was the M249 which was being left behind in favour of a MK48 and M240 combination.

Basically, the troops were happy to rely on 5.56mm in the short ranges of Iraq, but when they got to the longer ranges in Afghanistan, they were delighted to get hold of 7.62mm MGs and rifles (even bolt-action rifles initially in the BA, for want of anything better). They found the 5.56mm weapons ineffective at longer ranges, while the 7.62mms did what they wanted. By far the most popular small arms in the BA sections are the 7.62mm GPMG and L129A1 Sharpshooter rifle. Even the BA's senior officers concerned with small arms regard the 5.56mm as having an effective range of only 300m (the emphasis being on effective - I am aware it can perform better than this on the target range).

You may say that this is all in the mind but I doubt that, on the basis of some of the first-hand reports I've heard. Even if it is, I wouldn't dismiss too quickly a factor which has such a powerful effect on combat morale.

LRRPF52

09-05-2012, 01:25 AM

Roger that Tony. 5.56 carbines and rifles are limited in effective range in the hands of Joe tentpeg. This is why it makes even more sense for a Grendel LMG, DMR, and SASS family of calibers/weapons, to cover the longer distances for dismounts. The 5.56 NATO LMG concept never really made a lot of sense to anyone.

One aspect that would make the Grendel LMG less of a pig is a lower cyclic rate, in conjunction with a constant-recoil system that allows faster on-target results for even an entry-level soldier with minimal training.

With Grendel LMG's DMR's, and SASS rifles built around the cartridge, we wouldn't be limited by the 50k psi bolt thrust capacity of the current AR15, so a 130gr load would do really well from all those weapons. The Mk46 and Mk48 could be transitional platforms for the caliber change, with a feed tray cover, feed tray, and barrel swap.

JASmith

09-05-2012, 01:57 AM

... - but they found that it was the M249 which was being left behind in favour of a MK48 and M240 combination....

You may say that this is all in the mind but I doubt that, on the basis of some of the first-hand reports I've heard. Even if it is, I wouldn't dismiss too quickly a factor which has such a powerful effect on combat morale.
Would the decisions be the same if one or both of the MK48 and M240 were chambered for the Grendel?

It is said that morale is a weapon in its own right. The last thing one wants is a soldier who feels his weapon is useless. At the extremes, that can happen with ineffective ammo or heavy ammo that doesn't allow enough rounds to be carried. It is probably why we don't see many .50 BMGs used in this role.

One thing is true -- the Grendel round is lighter than the 7.62 NATO. Also, as you know, many of us argue that the other side either won't see the difference in effectiveness or the improved ability to hit with the Grendel will make him less comfortable. That would be a good thing...

Tony Williams

09-05-2012, 02:02 AM

The 5.56 NATO LMG concept never really made a lot of sense to anyone.

The BA didn't have one before Iraq - they had an IAR instead (L86 LSW). As a result of the close-range fighting in Iraq they decided they needed the ability to put down a higher volume of fire, so they bought the Minimi in short-barrelled Para form with a telescoping stock. Opinions as to its effective range vary between 200 and 300 metres...

LRRPF52

09-05-2012, 03:23 AM

I recall reading about what an abortion the L86LSW was when I was a kid in the 1980's. I carried the M249E2, and Para-SAW quite a bit myself. I would say that M855 is effective out to 200-300m in the hands of most soldiers. With optics and experience, that can be extended to 500m, but a 62gr pill isn't ideal really past 300m.

The 77gr Mk262 in the hands of a well-trained shooter can be reasonably effective out to 650m from a free-floated gun with decent optics.

The SAW's biggest problem is that it is way too bulky & heavy for what it is, and it isn't reliable, being based on the AK piston, bolt carrier, and bolt in a short sheet steel receiver that beats itself apart like an AK. The SAW can become a liability really quick. They did a PIP (Product-Improved Program) on it, supposedly reenforcing the receiver, along with the external addition of a telestock. The US & UK could put pressure on each other to fix this problem, because FN really dropped the ball when they made the Minimi.

From my viewpoint, a Squad-Level LMG needs to push a 130gr high-SD projectile at a decent velocity, so that it is effective out to 800m on point targets with optics, and really shines from 300-600m. With such a weapon, I would never need an attached GPMG team with a 7.62 belt-fed pig.

Tony Williams

09-05-2012, 07:52 AM

LRRPF52

09-05-2012, 03:17 PM

The L86A1 had various problems, but it went through HK's magic repair shop and is now a decent weapon. It is very accurate and the long barrel means it can squeeze all there is to get from the 5.56mm cartridge. It's still shorter than an M16.

There's no way you can have a viable LSW that is 30rd mag-fed, and especially not one that prevents you from elevating while in the prone because of the mag.

http://www.military-page.de/waffen/sturm/sa80/bild_sa80_10.jpg

With a 20rd mag chambered in Grendel, it could make a nice SASS platform if the barrel is floated, as it appears to be at least in the fore-end area on the L86A2. The trigger link would need to be modeled after the DSR-1 to be light, but they are finicky to field conditions and need tuning & lots of TLC.

There's not much worse than a dead trigger, or firing without the trigger being pulled.