Grendel as a Universal Infantry Cartridge

[JASmith]

...You are using data based off of a 123 Lapua Scenar match grade bullet in comparison with M-80. Two different animals with huge differences in quality and particularly cost...Reduce it to a rational ball round and then things change real fast.

LR55,

We've had this discussion before -- and, except for the M855 experience, I do not have data to suggest a more optimistic ballistic coefficient than you suggest. So, incorporating the "more mundane" ballistic coefficients is why the "Battle Rifle Cartridge" study listed above suggests that the Grendel is a little shy of being good enough by the standards of that discussion. The "6.5 mm and the Politics of Procurement" discussion uses the Scenar and and is looking at a full-length cartridge, so the service that adopts it would need to do a more-or-less complete replacement of infantry firearms. These folks are somewhat more optimistic with their views on realizable ballistic coefficients and their consensus is that a BC of about .52 might be attainable in a production 8 gram (123 grain) bullet. BTW, it looks like one would need 40-44 grains water capacity to get the desired 800 meter/second muzzle velocity in a 20" barrel.

So far, I tend to agree with RFB and my view has always been that the Army can design a bullet for the 5.56 that is more lethal on humans if the Army wants to.

The M855-A1 claims to do that. I am curious about how well this round fulfills the promise and what its ballistic coefficient is.

A question though. Why the 1100 meter lethality range? I mean, what is the rationale for that distance?

Ah.. this is one of the challenges of referring to three different studies to inform a debate. They each have different objectives and constraints. The 1100 meter requirement is from the discussion in Tony William's "6.5 and the Politics of Procurement" discussion. Here the desire is to replace both cartridges with a single ammunition type for the roles up to and including the GPMG. Further, the thought is that the cartridge must be demonstrably equivalent to the M80 in terms of penetration and lethality at 1100 meters.

--Joe

[LR1955]

These folks are somewhat more optimistic with their views on realizable ballistic coefficients and their consensus is that a BC of about .52 might be attainable in a production 8 gram (123 grain) bullet....Ah.. this is one of the challenges of referring to three different studies to inform a debate. They each have different objectives and constraints. The 1100 meter requirement is from the discussion in Tony William's "6.5 and the Politics of Procurement" discussion. Here the desire is to replace both cartridges with a single ammunition type for the roles up to and including the GPMG. Further, the thought is that the cartridge must be demonstrably equivalent to the M80 in terms of penetration and lethality at 1100 meters. --Joe

Joe:

I would like to see someone design a lead core and full metal jacket 6.5 bullet with a .5 BC and who can mass produce it while maintaining quality standards. Most likely some sort of hybrid between a secant and tangent ogive whose QC must be about ten times better than the current production line to maintain quality and actually show a significant improvement. I am sure it can be done but I bet that the costs would be astronomical to maintain quality standards.

I think you about max out the velocity capability of the cartridge given commercial powders with a 110 - 115 grain bullet. When you start going over 120 grains, you start to lose pretty good chunks of speed for every five grains of bullet weight. May not matter for competitive shooters but I tend towards favoring velocity over bullet weight for ball ammo use. That opens up another debate.

I understand the requirement is set at 1100 for GP machineguns. I am questioning the rationale for that distance. Guys can't see that far, can't estimate the range well enough to be effective, can't even see tracer well enough at those distances to determine if they are even close unless they use very big and very heavy thermals with spotters, any hit would be random chance and lethality would be more viewed an Act of God than even random chance.

So, perhaps in favor of the Grendel, I am questioning the distance because it is irrational in practical terms.

LR1955

[JASmith]

I would like to see someone design a lead core and full metal jacket 6.5 bullet with a .5 BC and who can mass produce it while maintaining quality standards.

That's why I'm very curious about how the M855 A-1 is performing. The web references indicate it has a steel insert for both a penetrator and a rather sharp nose. It's drag characteristics are claimed to be at least as good as the M855, which is a lot better than the shape factor suggested by the M80.

....favoring velocity over bullet weight for ball ammo use. That opens up another debate...

I can see good reasons why 2750 t0 2850 ft/sec at the muzzle are considered OK velocities for bullets with the M80 and M855 class of drag characteristics. Among other things the 300 meter drop increases rapidly at lower velocities and the payoff for increasing velocity gets progressively worse above this.

...I understand the requirement is set at 1100 for GP machineguns. I am questioning the rationale for that distance... ...Guys can't see that far, can't estimate the range well enough to be effective, can't even see tracer well enough at those distances to determine if they are even close...

I think you're right, we should have debates on both the preferred muzzle velocity for military-class bullets and on what constitutes effective shooting in an environment where the targets are generally concealed difficult to see.

While important to the current thread, discussing them in detail here may make tracking the key points challenging. The "6.5 and Politics of Procurement" is an example of a thread with a lot of good info, but the digressions made it so long that it is truly difficult to pull out the gems.

Cheers!
Joe

[warped]

M855A1 is a dog, it was poorly made and eats bbls.(powder,loose tips etc.)
It really does not help much.

There are other off the shelf bullets that would be far better.

[JASmith]

Warped,

Thanks! That's good information.

Do I gather that the accuracy isn't as good as the earlier M855?

One would think that the Army development folks would have done better after having tested "a million rounds" of the stuff!

Regarding "off the shelf" items: Seems like there are some conflicting requirements. Many of the European countries seem to be strict adherents to the agreement that one does not use deforming bullets but are OK with lead cores. The US, on the other hand, is OK with bullets that "just happen" to come apart in certain circumstances, but is damn near scared to death of lead -- a substance that humans have used and been exposed to for millenia!

[longdayjake]

I don't understand this fear of lead. It's not like there are enough bullets going into the water supply of the quantity needed to cause any kind of harm. The only lead poisoning that we should be afraid of is high-speed lead poisoning. The kind that leaves a massive hole as it exits.

[JASmith]

longdayjake,

At the risk of heading off on a tangent -- you are probably closer to the mark than not. Lead in paint, eaten by young children in has indeed been shown to cause health issues. This led to a fair bit of negative publicity and the anti-gun community saw an opportunity to make things more difficult for the shooting public...

So, yes, they are afraid of high-speed lead poisoning...

Back to the center of the thread: Regardless of the accuracy of condemnation, the reality we face is that US military small arms bullet design is rapidly moving away from lead. My view is that we need to accommodate that reality.

By keeping the discussion separate from how a bullet generates lethality (i. e., expansion, break-up, or tumbling) we can better concentrate on how to get the bullet to the target with enough mass, energy and momentum to have the potential to cause the requisite damage or injury. This accommodates the notion that at least one of the major users of small arms is moving towards bullets with a specific gravity of 7.8 to 8.0 and another takes pains to keep bullets from expanding or breaking up.

[warped]

Warped,

Thanks! That's good information.

Do I gather that the accuracy isn't as good as the earlier M855?

One would think that the Army development folks would have done better after having tested "a million rounds" of the stuff!

Regarding "off the shelf" items: Seems like there are some conflicting requirements. Many of the European countries seem to be strict adherents to the agreement that one does not use deforming bullets but are OK with lead cores. The US, on the other hand, is OK with bullets that "just happen" to come apart in certain circumstances, but is damn near scared to death of lead -- a substance that humans have used and been exposed to for millenia!

As always the best solution will always have a negative in there somewhere.

If it is for barrier penetration, it may not incapacitate, if it is for terminal effect, it may not penetrate blind barriers.

The other problem is will it even be accurate enough to be used past 400m, let alone 600m?

[RedFalconBill]

Joe,

The M855A1 bullet is designed to be a LF version of the original bullet. It is not designed to be an enhanced bullet, other than being lead free. Because of this, it will suffer from all of the issues that the M855 bullet does, plus the added cost stemming from increased production costs.

Also, they have had to get pressure waivers because it is a single source special power and a single source primer. Great, added cost with no increased effectiveness. It is not as accurate as std. M855, but still within spec...barely.

Big Army is still thinking that we are going to be fighting in the Fulda Gap and having to shoot hordes of Ivan Ivanovic's who wear soft body armor and have to shoot at steel helmets at 1/2 mile.

Using Ballistic Gel at 50m, M-855 ammo, when fired from M-4's, has a neck length of 6"+. Not very impressive, which only gives people more ammunition to dislike the 5.56 round, when it is the bullet more than anything else.

I too do not think that you can maintain QC on what is essentially match bullets by the tens of millions, at least not at a price that the DoD is willing to pay.

20" Barrels are going to go the way of $0.10 Beer and $0.25 Gas. 12.5" to 16" barrels are going to be the norm. Here, you would see a 100-110 grain bullet with an initial MV of 2,450 to 2,600 fps.

Personally, I think that the 5.56 is TOO much of a compromise, but we have been using it for over 45 years and the people I shot with it, stayed shot.

The somewhat extended ranges that we are seeing in Afghanistan only highlight what has been known since the First World War. At ranges 400m +, individual soldiers shooting at point targets is useless, essentially. This is the purview of the Designated Marksman or Machine Gunner. Soldiers do not estimate range very well, nor do they take wind into account, so without training it would not matter if they had a round that was more effective, because they would still miss.

[JASmith]

20" Barrels are going to go the way of $0.10 Beer and $0.25 Gas. 12.5" to 16" barrels are going to be the norm. Here, you would see a 100-110 grain bullet with an initial MV of 2,450 to 2,600 fps.

Are you suggesting that 2450-2600 ft/sec is a desirable MV, or are you indicating that that's all we might get from a particular cartridge?

Personally, I think that the 5.56 is TOO much of a compromise, but we have been using it for over 45 years and the people I shot with it, stayed shot.

What do you have in mind for cartridge more suited to our needs?

...Soldiers do not estimate range very well, nor do they take wind into account, so without training it would not matter if they had a round that was more effective, because they would still miss.

Does this mean that the solution is better and more training and stay with the same cartridge?

Cheers!