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Grendel as a Universal Infantry Cartridge - stanc - 08-29-2011
Variable Wrote:You sound like me heading to Guam with a PACAF flash on my beret and then finding out only after I got there that I was actually in SAC. Talk about a shocker!:eek: Everyone at Lackland had been telling me how laid back PACAF was, and how easy I'd have it there. I stepped into the gauntlet without even having a clue!Heh, heh, heh. My pleasure.
B-47? Bwaaahahahaha!At least the "BUFF"s are still flying. Now I feel young again!
Thanks!LOL
Yeah, they retired the B-47s after I was there about two years. Then my buddies and I were transferred to MAC (which at that time may have still been called MATS, I don't recall for sure) and sent to Midway Island, to refuel C-130, C-133 and C-141 transports going to and from Vietnam.
One day an RB-47 showed up to check out the island for use as a possible base of operations for recon flights over China or Russia, or so we were told. That idea was quickly scuttled when the aircrew saw that hundreds of goonie birds nested and flew around there. Stratojet engines didn't digest big birds at all well, so the RB-47 departed the next day and never returned...
Grendel as a Universal Infantry Cartridge - stanc - 10-19-2011
Possible bullet design for 6.5 Grendel assault rifles?
Below: 7.62x39 123gr / .300 Blackout 125gr
![[Image: img7045h.jpg]](http://img202.imageshack.us/img202/996/img7045h.jpg)
Grendel as a Universal Infantry Cartridge - JASmith - 10-19-2011
Stan,
Are you thinking of a linear scale (length and diameter) or just reducing the diameter?
The linear scale would give a bullet right at 80 grains, while reducing the diameter would be about 92 grains.
This could be a path to getting 3000 ft/sec. The long nose may make up for the lack of boat tail for ranges typical of infantry engagements.
The design looks like it could readily tumble when hitting something.
Grendel as a Universal Infantry Cartridge - stanc - 10-19-2011
JASmith Wrote:Stan, Are you thinking of a linear scale (length and diameter) or just reducing the diameter?Joe, I actually hadn't given it any thought. But, since you ask, I'm guessing it'd have to be a linear scale in order for cartridge OAL to fit in the magazine.
Quote:The linear scale would give a bullet right at 80 grains, while reducing the diameter would be about 92 grains.That's kinda what I had in mind, too.
This could be a path to getting 3000 ft/sec. The long nose may make up for the lack of boat tail for ranges typical of infantry engagements.
Quote:The design looks like it could readily tumble when hitting something.Concur. I dunno if the PDF below has a gel test for this bullet. Since the file size is 8MB, I didn't try opening it.
http://300aacblackout.com/resources/300AACBlackout06OCT2010.pdf
Grendel as a Universal Infantry Cartridge - JASmith - 10-19-2011
stanc Wrote:,,,I dunno if the PDF below has a gel test for this bullet. Since the file size is 8MB, I didn't try opening it.I looked over the PDF -- lots of gel tests on:[INDENT] Hornady 110gr V-Max
http://300aacblackout.com/resources/300AACBlackout06OCT2010.pdf
Speer 125gr TNT
Nosler 125gr Ballistic Tip
Remington 125gr Accutip
Sierra 125gr Pro Hunter JSP
Hornady 130gr SP
Barnes 110gr TSX
[/INDENT]
But, there appeared to be no FMJ bullets in the tests.
Grendel as a Universal Infantry Cartridge - stanc - 10-19-2011
JASmith Wrote:I looked over the PDF...there appeared to be no FMJ bullets in the tests.Uhhh...did I neglect to mention it's not FMJ? :o
It's a Sierra MatchKing. With secant ogive!
Midway has 'em (except reportedly without the cannelure).
http://www.midwayusa.com/Product/915404/sierra-matchking-bullets-300-aac-blackout-308-diameter-125-grain-open-tip-match-otm-box-of-500
Grendel as a Universal Infantry Cartridge - JASmith - 10-19-2011
Thanks for the link. The operative ballistic coefficient is 0.338 G1.
Gel block tests for this one should be interesting.
Grendel as a Universal Infantry Cartridge - LRRPF52 - 10-19-2011
I don't see what would be wrong with putting a short boat tail on this, like the M193 55gr. Either way, that would be a great assault rifle load, especially if it was screaming at 2900fps. The longer we can extend the 2600fps lead shower threshold, the better. This would mean a thin jacket, and the cannelure helps with jacket separation in conventional projectiles. Put a penetrator buried in the core of the bullet, with a concealed hollow-point, and now we're talking multi-purpose.
Grendel as a Universal Infantry Cartridge - stanc - 11-20-2011
LRRPF52 Wrote:I don't see what would be wrong with putting a short boat tail on this, like the M193 55gr. Either way, that would be a great assault rifle load, especially if it was screaming at 2900fps. The longer we can extend the 2600fps lead shower threshold, the better. This would mean a thin jacket, and the cannelure helps with jacket separation in conventional projectiles. Put a penetrator buried in the core of the bullet, with a concealed hollow-point, and now we're talking multi-purpose.You've used the "lead shower" phrase in other threads, and I always thought you were talking about the ability to hit the target with 5.56 more rapidly than with a higher-recoil round like 6.5 Grendel.
It looks like you actually mean the ability of the projectile to break up into multiple fragments?
![[Image: M855.jpg]](http://firearmstactical.com/images/Wound%20Profiles/M855.jpg)
Grendel as a Universal Infantry Cartridge - LRRPF52 - 11-20-2011
Not only break apart, but the lead core blows apart into a shower of dust. I think the term "lead shower" comes from the x-rays of 5.56 injuries that have been documented.
I prefer actual x-ray photos, not artist drawings, although the drawings you referenced basically represent what happens:
![[Image: LeadShower.jpg]](http://i1085.photobucket.com/albums/j422/LRRPF52/LeadShower.jpg)
![[Image: LeadSnowstorm.jpg]](http://i1085.photobucket.com/albums/j422/LRRPF52/LeadSnowstorm.jpg)
The tissue on guys I've seen who were shot with 5.56 looked like someone took an M80, buried it under their muscles surgically, then detonated it. Explosive hamburger...
The one who survived that was shot in the arm had basically Titanium rods and screws to replace the ulna and radius, which were fragmented so badly that only the heads, styloid processes, and olecranon were left...the main shafts of the bones had been fragmented into a bunch of small crumbs, like Captain Crunch cereal.
Grendel as a Universal Infantry Cartridge - stanc - 11-20-2011
LRRPF52 Wrote:Not only break apart, but the lead core blows apart into a shower of dust. I think the term "lead shower" comes from the x-rays of 5.56 injuries that have been documented.Judging by those pics, "lead shower" is a very apt description.
I prefer actual x-ray photos, not artist drawings, although the drawings you referenced basically represent what happens...
But it also brings up another point: One of your objections to replacing 5.56 NATO with 6.5 Grendel in carbines is that with a muzzle velocity of circa 2600 fps, there won't be such a "lead shower" beyond muzzle contact distance.
The trouble is, M855 is being phased out, replaced by M855A1. Since there is no lead in the M855A1 bullet, it cannot produce such a shower of tiny particles. At most there will be only a few large pieces -- the steel tip, copper slug, and jacket.
Even if a 6.5 M855A1-type bullet doesn't fragment, the greater mass and size may compensate. Plus, UK and European armies use non-fragmenting 5.56 bullets, so going to a non-fragmenting 6.5 round seems like it could only improve terminal performance for them.
Grendel as a Universal Infantry Cartridge - LRRPF52 - 11-20-2011
stanc Wrote:Judging by those pics, "lead shower" is a very apt description.
But it also brings up another point: One of your objections to replacing 5.56 NATO with 6.5 Grendel in carbines is that with a muzzle velocity of circa 2600 fps, there won't be such a "lead shower" beyond muzzle contact distance.
The trouble is, M855 is being phased out, replaced by M855A1. Since there is no lead in the M855A1 bullet, it cannot produce such a shower of tiny particles. At most there will be only a few large pieces -- the steel tip, copper slug, and jacket.
Even if a 6.5 M855A1-type bullet doesn't fragment, the greater mass and size may compensate. Plus, UK and European armies use non-fragmenting 5.56 bullets, so going to a non-fragmenting 6.5 round seems like it could only improve terminal performance for them.
Which is why I like M193 so much, but still like to have the penetrating ability of Green Tip at times. If it was up to me, carbines would have a 1/9 or looser twist with M193, but still be able to stabilize 62gr M855...but then you lose the ability to spin 77gr enough for distance work with anything slower than 1/8.
Unless things have changed, I thought our NATO partners were using M855, although with less power in the British and French loadings due to the limitations of the L85's op-rod system, and the non gas-operated FAMAS, which shreds brass cases like an ADHD child on a midnight Halloween binge through his pillowcase full of legal crack.
Right now, the M4/M855 combo fills a huge set of shoes that will take a comprehensive and exhaustive approach to replace AND provide real benefits to dismounted infantrymen and actual combat arms personnel. It is no easy task to do.
Grendel as a Universal Infantry Cartridge - stanc - 11-20-2011
LRRPF52 Wrote:Unless things have changed, I thought our NATO partners were using M855...Like the US, they copied the original SS109 bullet.
But, also like the US, the UK (and, IIRC, some other countries) made changes to the basic design.
I don't remember where I read it (Maybe on Tony Williams' site?), but my info is that the first version of SS109 used by the Brits fragmented like M855, so it was redesigned with a thicker jacket specifically to prevent fragmentation.
Also, the Swiss company RUAG currently markets an unleaded version of SS109 which is advertised as non-fragmenting.
IIRC, the Swedish SS109 is also reportedly non-fragmenting.
Grendel as a Universal Infantry Cartridge - LRRPF52 - 11-20-2011
stanc Wrote:Like the US, they copied the original SS109 bullet.
But, also like the US, the UK (and, IIRC, some other countries) made changes to the basic design.
I don't remember where I read it (Maybe on Tony Williams' site?), but my info is that the first version of SS109 used by the Brits fragmented like M855, so it was redesigned with a thicker jacket specifically to prevent fragmentation.
Also, the Swiss company RUAG currently markets an unleaded version of SS109 which is advertised as non-fragmenting.
IIRC, the Swedish SS109 is also reportedly non-fragmenting.
Yeah, I read on D. Water's 5.56 timeline that the Swedes felt that the M193 and 1/12 rifling was inhumane, so they apparently had some input into driving the direction of the NATO /7 twist for the 5.56 NATO 62 gr M855 to be 1/7 so that it would fragment less, but thin jackets help it do it anyway in the US loadings. Since Sweden is not even a part of NATO, and is one of the most non-combative nations now, I don't see why anyone would take any input from them on small arms wound ballistics, although they are the go-to guys for rockets, steel, artillery pieces, and other excellent war material they sell to us heathens, while assuming an air of moral superiority in the global scheme. I have close relations with Sweden, to include ancestry and living relatives, so I reserve the right to place criticism where it is due with them, especially from my Finnish side...lots of rivalry there.
You are fighting in the opposite direction with people who are looking for humane small arms cartridges when dealing with that mindset. I want the bullet to come apart, since the steel penetrator is for hard targets anyway. Thin jackets and 2600+ fps does the job fine.
Grendel as a Universal Infantry Cartridge - stanc - 11-20-2011
LRRPF52 Wrote:Yeah, I read on D. Water's 5.56 timeline that the Swedes felt that the M193 and 1/12 rifling was inhumane, so they apparently had some input into driving the direction of the NATO /7 twist for the 5.56 NATO 62 gr M855 to be 1/7 so that it would fragment less...I'm pretty sure the Swedes had nothing to do with the choice of 1:7 twist. That was dictated by the requirement to stabilize the very long L110/M856 Tracer bullet.
Grendel as a Universal Infantry Cartridge - LRRPF52 - 11-20-2011
stanc Wrote:I'm pretty sure the Swedes had nothing to do with the choice of 1:7 twist. That was dictated by the requirement to stabilize the very long L110/M856 Tracer bullet.
I've always understood that as well, but there seems to have been consideration for a 1/9 rifling for the rifles.
Grendel as a Universal Infantry Cartridge - stanc - 11-21-2011
LRRPF52 Wrote:I've always understood that as well, but there seems to have been consideration for a 1/9 rifling for the rifles.IIRC, 1:9 was considered for rifles, since that twist is adequate to stabilize 62gr M855, while also providing better accuracy (than 1:7) with 55gr M193.
However, the decision makers were apparently knowledgeable enough to realize that small unit leaders and others often use tracer ammo for signalling, fire direction, etc, and so chose the 1:7 twist with that in mind. Good thing, too, as it enabled bullets like the 77gr MatchKing to be used in carbines and rifles.
Grendel as a Universal Infantry Cartridge - stanc - 11-21-2011
LRRPF52 Wrote:Right now, the M4/M855 combo fills a huge set of shoes that will take a comprehensive and exhaustive approach to replace AND provide real benefits to dismounted infantrymen and actual combat arms personnel. It is no easy task to do.For sure. I wish we had test data to compare 5.56 M855A1 with the same type of bullet in 6.5 Grendel. Unfortunately, published test info on 5.56 M855A1 is negligible, and the 6.5 version is apparently (and understandably) a "back burner" project with AA at present. It may be years before we can get anything close to a definitive comparison and evaluation.
Grendel as a Universal Infantry Cartridge - BluntForceTrauma - 11-21-2011
Reading an article about the origins of 5.56 M855A1 ammo yields this quote that corroborates both sides of the M855 effectiveness argument:
"In essence, all of the anecdotal evidence was correct the M855 could be highly lethal, or highly ineffective, depending on circumstances which the user could not control."
Source link click here.
John
Grendel as a Universal Infantry Cartridge - stanc - 11-21-2011
Great find, John! Excellent article. Good info.
(And provides answers to all the critics of the M855A1 program.)