Grendel LMG

[stanc]

The Visegrad 4 have already been looking at new weapons systems.

I know the Czechs are fielding the CZ805, but I couldn't find any indication that Poland or Hungary were planning to replace their AK variants.

The Kreb's kits and Brugger & Thommet rails make an AK an even more ungainly beast of an Assault Rifle.

No kidding. Hungarian AK63 MF

I don't see a need for them to load the same projectile for assault rifles and LMG's anyway... There is zero reason to have a strictly belt-fed LMG use the same projectiles as a mag-fed AR.

Granted, but isn't that what everybody does (except the Chinese)?

[bwaites]

Interesting. Are you sure your bullets don't have tungsten cores?

I was going by info on the Swedish military ammo website for weight of the steel-core AP, so I can't verify the accuracy of the 113gr figure.

Well, I can check again, but I'm pretty sure they were magnetic.

Going to be next week, though, I'm in the middle of a garage/loading room remodel.

[RangerRick]

A college room mate of mine is a retired Army bird Colonel. He was a Special Forces Officer and Polish speaker. He helped the Poles set up their Special Forces school as a special project right before he retired.

If we get anywhere with this I can approach him about a contact point there.

I have a belt on order from DS Arms. I'll post picks with Grendel brass and 7.62x39 brass in it side by side. I'll load up some Norma FMJs to 2.205 and see how much powder we can get in.

Rick

[stanc]

A steel penetrator design based off the 7N6 or 7N10 would facilitate the same velocities as a standard FMJ.

I haven't seen a sectional view of the 7N6 and 7N10, but in any case, what I was thinking of is the use of mild steel cores in 7.62x54R ammo, and the possibility that the V4 would also use the same construction in bullets for 6.5 Grendel, should they adopt it.

Just look at the 5.45x39 velocities for those at 2900 fps out of a 16.3" barrel, with projectile weights at 56gr. M4 with M855 62gr out of 14.5" barrel is 2900+. A 120gr 6.5 running quick with the narrow steel rod would smoke some steel.

Maybe, but you're not going to get anywhere near 2900 fps with a 6.5 120gr. According to Bill W, in a 19.5" barrel the 123gr SMK ammo from Black Hills did only 2550-2575 fps, and he considered that a hot load. If MV is kept down to 2500-2525 fps, it'll only be doing ~2400 fps from a 14.5" tube.

Either way, you're looking at no less than 4 different projectiles for the dismount force logistics structure: Standard AR load, Standard LMG, AP, Tracer.

IMO you're being optimistic about getting two different Ball loads adopted, but otherwise I agree.

I think for the near term, what's most needed is a good Ball projectile, most likely non-fragmenting FMJ (assuming the V4 intend to continue strictly abiding by Hague Declaration III).

Notice we haven't even covered DM/Sniper, which is where this cartridge really shines as well, with the 123gr Scenar/SMK types.

True. That's for another thread, perhaps.

[bwaites]

You may already be aware that some 6.5x55 FMJs had steel jackets, which would also be attracted to a magnet.

Unless there is a copper colored steel, these have a copper jacket, lead inside the base, and a steel tip. The bottom of the projectile is not magnetic, as I recall.

[stanc]

Unless there is a copper colored steel...

Steel jackets can be copper colored. There are gilding metal clad steel (GMCS) jackets, and copper washed steel jackets.

...these have a copper jacket, lead inside the base, and a steel tip.

Let me get this straight. Does it have a short, steel tip (with long, lead base slug) similar to M855 Ball?

Or does it have a long, steel core with pointed tip (and a small lead plug at the base)?

The bottom of the projectile is not magnetic, as I recall.

If it won't stick to the jacket at the base, then it must not be a steel jacket.

[JASmith]

Using the expression KE Density = (1/2)MV²/(πR²) (where M=mass, V=velocity, and R=bullet radius) I find that the Grendel is about 100 ft/sec shy of matching the 7.62X51 M80 potential for perforating steel plates for lead-core FMJ bullets in the 100 - 120 grain class.

Replacing all or part of the lead with a hardened pin as is done with the M855A1 would change this to the extent that the Grendel with a 20-24 inch barrel might just be able to perforate the same thickness of steel as the M855A1.

Of course we would need to test. Before that, someone needs to design and fabricate steel-cored 6.5 bullets in the 100-120 gr weight range, develop safe loads and verify with load development testing. Then, at last, we could see if the Grendel might do as well.

Any takers on bullet fab?

In the meantime, I'm happy with knowing that the Grendel is close and maybe good enough!

[stanc]

Of course we would need to test. Before that, someone needs to design and fabricate steel-cored 6.5 bullets in the 100-120 gr weight range, develop safe loads and verify with load development testing. Then, at last, we could see if the Grendel might do as well.

Or, we could do comparison tests with the lead-core Norma 120gr FMJ vs 7.62x54R (or 7.62x51) lead-core FMJ. That would let us see how well Grendel can do now, instead of waiting years for someone to design and fabricate steel-core bullets, then develop and verify safe loads.

In the meantime, I'm happy with knowing that the Grendel is close and maybe good enough!

Personally, I'd rather see proof, than depend upon a maybe.

[JASmith]

The the 7.62X51 NATO kind of clones the velocity for bullet weight of the 7.62X54R in bullets of the 140 - 175 grain class. (As an aside, the NATO round appeared about 60 years after the Russian round - talk about progress!)

Since we're already pretty sure the Grendel doesn't quite get the needed energy density to punch the same plate as the .308, we should be surprised if it does any better against the Russian round.

Why test when one is reasonably sure the outcome isn't what you want? The bullet designs suggested will likely 'prove' what we already know. That will do nothing to help...

One more time -- Inappropriate testing is likely to be harmful to keeping the momentum going.

[RangerRick]

I don't see a need for them to load the same projectile for assault rifles and LMG's anyway, since they have had different end-user logistics packages for PKM's, MG3's, Vz's, SVD's, AK74's, MPi-AKS-74N's, Tantals, and so forth. A steel rod penetrator like the 7N6 or 7N10 would be great, with plenty of lead weight, and a thin projectile jacket. There is zero reason to have a strictly belt-fed LMG use the same projectiles as a mag-fed AR.

I would disagree with this if you can't fire the LMG rounds in the rifle and vice versa. If you have different rounds, the zero would be different and that would negate the whole point of ammo commonality.

I know I've stripped rounds from 7.62 belts for M-14 sniper rifles when we ran out of sniper ammo. I also know of guys who gathered up expended links and assembled belts for the machine guns when they only got rifle ammo resupply.

Things can get chaotic sometimes.

It may be a moot point as all of these countries are now in Nato and will likely refit with Nato standard ammo when they refit, except perhaps Special Ops forces.

[RangerRick]

Or, we could do comparison tests with the lead-core Norma 120gr FMJ vs 7.62x54R (or 7.62x51) lead-core FMJ. That would let us see how well Grendel can do now, instead of waiting years for someone to design and fabricate steel-core bullets, then develop and verify safe loads.

Personally, I'd rather see proof, than depend upon a maybe.

The 7.62x54 is more powerful than the 7.62x51 NATO. It is closer to the 30.06. So the comparison would favor the x54.

The idea is that you can have a light machine gun of acceptable power with much less weight and ammo commonality with your rifles. The comparison should be the RPD in 7.62x39 and the RPD in Grendel.

You could do the x54 comparison for reference, but no way will the Grendel match it, even at long range.

You can demonstrate the weight difference, though. The Grendel ammo will be much lighter than the x54. As a percentage even more than the x51.

[RangerRick]

Sounds good.

Cool. By chance did they give you a delivery date?

Not yet, but the money is gone from my checking account so it better be soon!

R

[JASmith]

I would disagree with this if you can't fire the LMG rounds in the rifle and vice versa. If you have different rounds, the zero would be different and that would negate the whole point of ammo commonality.

I know I've stripped rounds from 7.62 belts for M-14 sniper rifles when we ran out of sniper ammo. I also know of guys who gathered up expended links and assembled belts for the machine guns when they only got rifle ammo resupply.

Things can get chaotic sometimes...

You make an interesting point. I think we are almost on the same page. One could visualize that a Grendel used by a sharpshooter or sniper would likely be shooting long range precision ammo with ballistics similar to those desired for the LMG.

This would be different than using M855A1 in an M4/M16 when the sharpshooter runs out of Mk262 but more or less equivalent with your description of the M14 and general purpose MG.

And yes, things get chaotic and there are times when the ammo you got is the ammo you use...

[stanc]

Since we're already pretty sure the Grendel doesn't quite get the needed energy density to punch the same plate as the .308, we should be surprised if it does any better against the Russian round.

Why test when one is reasonably sure the outcome isn't what you want?

To gain knowledge. Without testing, we do not actually know what the outcome will be. If nothing else, test data for the current bullet would give us a baseline to guide improvements.

One more time -- Inappropriate testing is likely to be harmful to keeping the momentum going.

Momentum? What momentum??? Momentum implies movement. How are we any further along than we were in 2005? Did some momentus development occur while I slept last night?

[JASmith]

...Without testing, we do not actually know what the outcome will be. If nothing else, test data for the current bullet would give us a baseline to guide improvements...

I am beginning to despair of finding the words to communicate a basic truth:

Absent a federal contract we are guaranteed to have tests that won't be credible except for those people who want to denigrate or destroy the Grendel.

This truth should not keep us from seeking tests but it should absolutely keep us from doing tests that we can reasonably expect to produce disappointing results.

[stanc]

The 7.62x54 is more powerful than the 7.62x51 NATO. It is closer to the 30.06. So the comparison would favor the x54.

The idea is that you can have a light machine gun of acceptable power with much less weight and ammo commonality with your rifles. The comparison should be the RPD in 7.62x39 and the RPD in Grendel.

I disagree. As I read it, the proposal by LRRPF52 is for a Grendel LMG "to provide the same downrange benefits as 7.62 GMPG's such as the PKM and MAG58." Since he also notes the potential for a one-caliber system using 6.5 Grendel, that means it would have to be good enough to not only replace 7.62x54R in the V4 armies, it would have to be good enough to not be outranged by the PKMs used by the Russian army (the threat for which the V4 nations created a military alliance).

You could do the x54 comparison for reference, but no way will the Grendel match it, even at long range.

I don't know if it's necessary to match terminal performance, although the closer we can get to equal performance, the better. More importantly, I think it's vital to match effective range, for the reason noted above.

You can demonstrate the weight difference, though. The Grendel ammo will be much lighter than the x54.

Absolutely, a comparison of weapon and ammo weights should be part of any presentation.

[stanc]

I am beginning to despair of finding the words to communicate a basic truth:

Absent a federal contract we are guaranteed to have tests that won't be credible...

Well, I know the feeling. I can't get you to understand that I'm talking about informal tests only to tell us where we stand at present, while you keep equating it with formal tests done for officialdom at some point in the future.

They are not the same thing, and the one is no less "credible" than the other. The formal testing you advocate has its place, but it isn't necessary in the early stages.

This truth should not keep us from seeking tests but it should absolutely keep us from doing tests that we can reasonably expect to produce disappointing results.

Since we're talking 120gr @ 2500-2550 fps, or 110gr @ 2600-2650 fps, versus 150gr @ 2750 fps, I'd say we can reasonably expect "disappointing results" regardless of what 6.5 bullet is tested...

[stanc]

Here's another reason why I think there should be comparison testing with the Norma 120gr FMJ.

The logical evolution of this project is the conversion of a belt-fed RPD to 6.5 Grendel. That will likely require financial support, either a lot of money from a few backers, or a smaller amount from many individuals.

Now, I can't speak for others (like Bill W, who's expressed an interest), but I know that before I'd commit my hardly earned cash to such a project, I would want to see evidence that it had some chance for successfully achieving the goal. That's why my OP stipulated two prerequisites: (a) Buy an RPD belt and see how well 6.5 Grendel rounds fit in it; (b) Do comparison testing of 6.5 FMJ vs 7.62 FMJ.

The rationale for (a) should be obvious. If the cartridges don't fit in the belt properly, there's no point in buying an RPD.

My reasoning for (b) is that it'd show relative performance with bullets of the same type. If terminal effects of 6.5 Grendel with lead-core projectiles isn't close enough to that of 7.62x54R with lead-core bullets, it'd be illogical to expect relative capability to be any better with steel-core bullets in each caliber, so again there'd be no point to buying an RPD.

However, if 6.5 Grendel rounds appear to fit okay in the 7.62x39 links, and if terminal effects/barrier testing showed at least the promise of near-7.62x54R performance, then it would be worth proceeding.

Rick has gambled $30+ of his own money to check (a). We can wait to see how that turns out, before taking the next step.

[JASmith]

...If terminal effects of 6.5 Grendel with lead-core projectiles isn't close enough to that of 7.62x54R with lead-core bullets, it'd be illogical to expect relative capability to be any better with steel-core bullets in each caliber, so again there'd be no point to buying an RPD...

Surprise! We don't need or want to equal or better the 7.62X51 bullet for bullet.

Performance of the 7.62X51 M80 round is the standard we are using. Even the pipsqueak M855A1 is claimed to be able to defeat some armors at least as well as the M80. And yes, those claims are supported by government or government-sponsored tests.

If steel-cored 6.5 bullets from the Grendel can equal or better both the M80 and M855A1 performance, then we have a case.

We are very sure that the lead-core FMJ won't get through the plates as well as the M80, or we would likely have already seen pictures of the event.

Let's look for testing that will build a case. Do it privately so that that case can be properly articulated with the right people. The testing will still not be viewed as credible because it won't be official, but it gets our foot in the door.

[stanc]

Surprise! We don't need or want to equal or better the 7.62X51 bullet for bullet.

I said nothing about doing better than 7.62x51. However, equal is desirable, and "close enough" is essential.

But, I do think you are mistaken about the "bullet for bullet" part. If each bullet type (Ball, Tracer, AP, Sniper, etc) doesn't give performance comparable to those of 7.62x54R/7.62x51, then the V4 militaries are unlikely to go for the idea.

If steel-cored 6.5 bullets from the Grendel can equal or better both the M80 and M855A1 performance, then we have a case.

Unless you have credible information that the V4 plan to use M855A1, its performance would seem to be irrelevant.

The pertinent round to compare against is Russian 7.62x54R.

We are very sure that the lead-core FMJ won't get through the plates as well as the M80, or we would likely have already seen pictures of the event.

Illogical conclusion. For one thing, nobody can photograph an event that hasn't happened. For another, until somebody actually shoots steel plates, cinder blocks, etc, with 6.5 FMJ, we can't know how it fares in that regard.

Let's look for testing that will build a case. Do it privately so that that case can be properly articulated with the right people. The testing will still not be viewed as credible because it won't be official, but it gets our foot in the door.

The "foot in the door" part is something I've argued all along. Glad to see you're finally coming around.

But at present, building a case to present to "the right people" is both unnecessary and premature. That can and should wait until optimized 6.5 bullets have been designed and fully developed.

What we need right now is to build a data base so that we can make decisions based on factual information, not beliefs or wishful thinking.