New Army "Caliber Configuration Study"

[stanc]

It appears to me, gentlemen, that there seems to be an element of naysaying based on thinking that "exceptions are the rule", rather than understanding that all rules have exceptions. From a grander sense, the tactics and scenarios being discussed are for the average conflict and engagement. What must be understood is that, regardless of the weapons deployed, the tactics employed and the logistics involved, there never be the perfect load out for every situation.

Having seen that, can we not stop nitpicking on every point, and see the bigger picture, here? It is well understood that there is an abundance of information available from which one may pick and choose to score points, but doing so does not invalidate the opposing viewpoint. Rather, it shows (at least to me) a narrow viewpoint, which does the writer no justice or this discussion any service.

If you're referring to me, I was not nitpicking, nor do I have an "opposing viewpoint," as I am open to the idea of 6.5 Grendel being a Unified Cartridge.

I addressed two major (and one minor) issues of John's scenario, in order to show significant problems with it. This was not done "to score points" (Which I couldn't care less about doing...unless there is money involved. ), but rather to provide valid information relevant to the subject.

I would ask how that does not help in seeing "the bigger picture"? (But, perhaps I should first also ask what you mean by that phrase?)

[NugginFutz]

What must be understood is that, regardless of the weapons deployed, the tactics employed and the logistics involved, there never be the perfect load out for every situation.

+1

[JASmith]

It appears to me, gentlemen, that there seems to be an element of naysaying based on thinking that "exceptions are the rule", rather than understanding that all rules have exceptions. From a grander sense, the tactics and scenarios being discussed are for the average conflict and engagement. What must be understood is that, regardless of the weapons deployed, the tactics employed and the logistics involved, there never be the perfect load out for every situation.

Having seen that, can we stop nitpicking on every point, and see the bigger picture, here? It is well understood that there is an abundance of information available from which one may pick and choose to score points, but doing so does not invalidate the opposing viewpoint. Rather, it shows (at least to me) a narrow viewpoint, which does the writer no justice or this discussion any service.

Well said!

Constant repetition of the narrow viewpoint with cherry-picked examples indeed do not help the larger discussion.

[stanc]

Well said!

Constant repetition of the narrow viewpoint with cherry-picked examples indeed do not help the larger discussion.

Will you or baba please enlighten me as to what is this "narrow viewpoint" of which you two write?

John asked if his scenario was workable. I demonstrated the flaws in it.

It'd be a disservice to John to say, "Yes, John... Your plan is not only workable, it's easily accomplished and is absolutely flawless!"

[BluntForceTrauma]

I guess I wasn't referring to the workability of particular counter-ambush tactics, but to the workability of a scenario wherein U.S. dismounts have two basic shoulder-fired weapons: 65G ARs and LMGs, along with a shoulder-fired, laser-ranged, air-burst grenade launcher (ABGL? ).

This, of course, doesn't negate the use of things like the M3 "Carl Gustav" or heavier crew-served machine guns when capability and necessity demand.

Another way of asking the question is: What does a dismounted patrol need doing, with only the weapons and ammo they can carry on their backs, that can't be done with the combo of 65G ARs and LMGs, and ABGLs?

With that mix, I'd question the need to bring along a 7.62N MMG or a .338LM MMG.

John

P.S. And when I say LMG I'm thinking belt-fed. Something like a Grendelized Knight's Stoner LMG, an Ameli, or a scaled-down PKM bullpup at about 10 lbs.

[JASmith]

John,

Babaganoush is right, there is no 'one size fits all' solution, but I maintain that your description is one of the best arguments for a cartridge having the Grendel characteristics.

I also, agree that the Grendel in the mix for dismounted infantry would obviate the need for the 7.62 on those dismounted patrols.

The only flaw in the point of view is that indicated by LRRPF52, and that is the need for very light ammunition for patrols that do not have access to immediate ammunition resupply.

The conversation is going in a good direction in spite of the occasional tug in other directions.

Thanks for starting it!

[BluntForceTrauma]

The only flaw in the point of view is that indicated by LRRPF52, and that is the need for very light ammunition for patrols that do not have access to immediate ammunition resupply.

And that's the beauty of a public discussion and getting all viewpoints on the table, to consider angles one would forget to factor in on one's own.

And if it were not for the proven effectiveness of 5.56, I'd make my slippery slope argument, saying if ammo quantity is the prime consideration then why not .204 Ruger, or, to absurdity, why not .22LR? Somewhere in the mix a baseline of "performance" needs to be specified, and a balance struck between quantity and performance. I'm still of the mind that 65G is that very narrow balance point.

John

[stanc]

What does a dismounted patrol need doing, with only the weapons and ammo they can carry on their backs, that can't be done with the combo of 65G ARs and LMGs, and ABGLs?

Ah, but that is a considerably different question than that of the scenario in your previous post.

If we assume that the significantly lighter, lead-free bullets would provide 7.62 range, and that a belt-fed Grendel LMG is actually doable, then I think such a weapons mix would be viable for foot-mobile infantry. (Although, as LRRPF52 keeps pointing out, the combat endurance of riflemen would be substantially reduced vs 5.56mm carbines, which would necessitate more frequent resupply.)

[BluntForceTrauma]

So, if I advocate using only 65G and 40mm ABGL for dismounted patrols, would anyone be comfortable advocating, instead, 5.56 and 40mm ABGL? Why, or why not?

The argument, theoretically, applies to the one as well as the other: ARs and LMGs — 65G or 5.56 — keep them pinned down and provide local protection for the ABGLs, which are the real killers, much as the Wehrmacht MG42s were.

Under that scenario, is the capability of the AR and LMG round in and of itself that important? Does quantity of 5.56 trump capability of 65G? Or does the overlap of 65G into 7.62 M80 territory trump 5.56 quantity?

I see cheap laser-ranged, air-burst grenades as a game-changing technology, just as the rifled bore made mass troop formations in open country inadvisable and 50 years later the machine gun made them suicidal. Infantry tactics were forced to change to open formations using organic cover. Now ranged grenades help solve the problem of neutralizing infantry under cover.

John

P.S. For the sake of calculations, each 5.56 M855 cartridge weighs 190 grains, 7.62 M80 weighs 393, 65G 123gr cartridge weighs 270.

1000 rounds, respectively, of M80 weighs 56 lbs., M855 27 lbs., 65G 39 lbs.

Or, 56 lbs. of M855 is 2063 rounds and 65G is 1452 rounds.

[stanc]

So, if I advocate using only 65G and 40mm ABGL for dismounted patrols, would anyone be comfortable advocating, instead, 5.56 and 40mm ABGL? Why, or why not?

Personally, I'd opt for 6.5/40mm over 5.56/40mm, mainly because of the 6.5 increased range.

The argument, theoretically, applies to the one as well as the other: ARs and LMGs — 65G or 5.56 — keep them pinned down and provide local protection for the ABGLs, which are the real killers, much as the Wehrmacht MG42s were.

What evidence is there to show the 40mm ABGL would be a better killer than the 6.5mm LMG? I've heard conflicting claims regarding effectiveness of the 25mm airburst rounds.

Under that scenario, is the capability of the AR and LMG round in and of itself that important?

Well, if the 40mm ABGL truly would be the "real killer" on the battlefield, far surpassing the hit/kill probability of the LMG, then I think caliber of the LMG wouldn't matter much.

Does quantity of 5.56 trump capability of 65G? Or does the overlap of 65G into 7.62 M80 territory trump 5.56 quantity?

In some situations, yes. In others, no. Overall, I can't be sure. Needs testing!

I see cheap laser-ranged, air-burst grenades as a game-changing technology, just as the rifled bore made mass troop formations in open country inadvisable and 50 years later the machine gun made them suicidal. Infantry tactics were forced to change to open formations using organic cover. Now ranged grenades help solve the problem of neutralizing infantry under cover.

You may be right. Personally, I think "game changer" is a vastly over-used phrase.

[cory]

Alright so I just took some measurements and ran some numbers. I think we can safely assume negligible change to empty magazine weight.

Let's compare a LC M855 round to a Hornady 123gr SST.

Using a RCBS 5-0-5 scale the weight of an individual round is as follows:

M855 - 188gr +-1gr
123gr SST - 271gr +-1gr

from a google search I used 1gr = 0.000142857143 lbm

Converting grs to lbm then multiplying by the current minimum combat load of 180 rounds we're looking at:

M855 180x = 4.83lbm
123gr SST 180x = 6.97lbm

While we're at it let's look at a load of 300 rounds.

M855 x300 = 8.06lbm
123gr SST x300 = 11.61lbm

So worst case we're looking at an ~3.5lbm addition to the combat load to give our grunts a much more capable carbine.

(If I've screwed my math up somewhere please let me know.)

Conclusion:
IMHO I think we can rule out significant addition to combat fatigue as a deciding factor.


Verification using a cheap food scale:
Winchester M855 x30 = 12.91oz
x10
M855 x300 = 129.1oz
/16
M855 x300= 8.07lbm

[BluntForceTrauma]

What evidence is there to show the 40mm ABGL would be a better killer than the 6.5mm LMG? . . . Personally, I think "game changer" is a vastly over-used phrase.

Think about it: Direct line-of-sight small arms cannot hit a Taliban behind a boulder who only pops out to launch an RPG or fire a burst from his PKM. You laze his boulder and explode an air-burst 40mm grenade 1 meter beyond it, above his head, your kill probability increases. (I agree 25mm is too small.)

I use the term "game-changer" advisedly. In this case, I feel it is as apt today as it was for the MG in 1914. Was it you, or someone else, who noted the Chinese are moving forward in this area?

John

[cory]

Expanding that analysis to include a 30rd 5.56 magazine and a 25rd Grendel Magazine.

I have a Pmag that weighs 5ozs and a GI mag that weighs 4ozs. We'll use the Pmag as a Grendel GI mag would probable have to be slightly stiffer.

10 Pmags weigh 3.125lbm - 300 5.56 rounds capacity
12 Pmags weigh 3.75lbm - 300 6.5 Grendel round capacity

We're looking at 3lbs to worst case 5lbs added to the combat load.

[stanc]

P.S. For the sake of calculations, each 5.56 M855 cartridge weighs 190 grains, 7.62 M80 weighs 393, 65G 123gr cartridge weighs 270.

P.S. A weight of 123gr is plausible in a lead-core HPBT bullet for DMR use, but not in a lead-free Ball projectile for general issue.

The Army has already fielded lead-free M855A1, and plans to field M80A1 this year. In the absence of info to the contrary, it's probably safe to assume (for this discussion) that both lead-free rounds weigh the same as M855 and M80.

A lead-free 6.5 Grendel projectile would likely weigh no more than 110gr, which means you can figure a ball round @ ~255gr. Don't penalize the 65G unnecessarily.

[stanc]

Think about it: Direct line-of-sight small arms cannot hit a Taliban behind a boulder who only pops out to launch an RPG or fire a burst from his PKM. You laze his boulder and explode an air-burst 40mm grenade 1 meter beyond it, above his head, your kill probability increases.

John, I'm very familiar with the theory, having read the US Army's Small Arms Master Plan, and written several articles on it.

My point is that we don't actually know how well the theory translates into reality.

IIRC, the max range on the 25mm round is only 700 meters, and that's against area targets; against point targets (i.e., individuals), 500 meters. That's far short of the maximum stand-off with the PKM and RPG attacks. Would a medium-velocity 40mm grenade achieve a 1000-meter range against point targets?

P.S. It was Tony who noted the Chinese advances in shoulder-fired grenade launchers. But, AFAIK, none of them fire airburst rounds.