Army 7.62 Replacement Rifle Search DOA

[globemaster3]

I'll be the first to give anything by the "X Times" (X=insert branch here) the stink eye for value added reporting, but it appears that the search for a new weapon for the Army in 7.62 has died on the vine.

http://www.armytimes.com/news/your-a...20Bird%20Brief

However, it did leave open that they are considering an intermediate round between 5.56 and 7.62.

I know this topic was under discussion in a couple other threads a few months ago, but can't seem to find the right one to resurrect.

[Deaf Smith]

Geeze guys... just use the 6.8 SPC and forget it. Individual General Issue rifle fire past 600 yards is dreaming.

If the DoD wants some of that they need a sharpshooter in each squad with a REAL sharpshooting rifle.

Deaf

[Danoobie]

They can't decide on anything from FN or H&K?
At least, I know where I'd be looking...

[hdwhit]

globemaster3 wrote:
However, it did leave open that they are considering an intermediate round between 5.56 and 7.62.

When I was a graduate student, one of my professors got a contract from the Army to do some computational work on a replacement for the 5.56x45. This was all computational stuff, no rounds were made or shot. What we ended up coming up with that met the specifications was a 6.5 mm bullet in the 100-120 grain range driven at about 2600-2800 fps. When we optimized the result, it required a different head diameter from anything that existed at the time. And since that represented all kinds of additional tooling and support costs, we knew our results weren't going anywhere. Still, if someone else can come up with an optimal package that has a head diameter of about 4/10 inch and an overall length of 2.260 or less, they may have designed the Army's new round.

[Sequins]

Why bother mixing it up. 7.62 is excellent.

[Fishbed77]

This project was dead before it ever started. It was just another excuse for some Army procurement officer to justify his existence.

[Stats Shooter]

It just isn't worth it to spend the billions with the gains being marginal at best.

There just isn't a one size fits all cartridge with the current firearms technology....which really has only marginally improved since the 1950's and 60's when the 762x51 and 556x45 were being developed and tested.
At 200 yards or less, the 556 is superior as it is lighter, holds more rounds, low recoil, easy follow up shots, and can be used for cab...but has enough oomph at 200-250 yards in a standard carbean.

At 300+, the .308 is great giving about a 600 yard max effective range (probably more but that was what it was when I was in), but can be easily used closer in until you get to cqb or suppressing fire.

The only claim you can make is that the 556 is too small for some applications and the .308 too big, so you just create a round ok at everything but not great at anything.
The short fat cartridges like the creedmore or short mags won't hold much more in a mag than .308.

Why not issue some soldiers a 7.62x51, and some a 556 for large scale engagements, or just issue a rifle mission specific. If you are clearing rooms, a pistol chambered carbean or 556. If you are in an urban environment, 556. If the battlefield is big, .308.

[Danoobie]

Mississippi hit on the army's major problem, IMO. They
are trying to shoehorn one caliber into all missions. You
just can't have it all in one round.

[T. O'Heir]

"...excuse for some Army procurement officer..." Senior officers need to be kept bust just like the OR's.
"...Why not issue some soldiers a 7.62x51 and some a 5.56..." That's what is done now. Despite the logistics nightmare it causes. However, the relative 'power' of the cartridge is not the issue. It's how much a PBI troopie can lug round. The typical PBI load is over 100 pounds. Every gram matters.
"...in an urban environment, 5.56..." Where it'd be totally useless. The 7.62NATO will shoot a cinder block into little tiny pieces(great fun it was too) while a 5.56 NATO will not.
"...can't decide on anything from FN or H&K?..." NIH. As in 'Not American'. S'why the M-14 was adopted over the much better battle rifle, FAL.

[Double Naught Spy]

LOL, yet AGAIN, the replacement program has failed to come up with a replacement. D'uh!

[Stats Shooter]

T.O'Heir: ..in an urban environment, 5.56..." Where it'd be totally useless. The 7.62NATO will shoot a cinder block into little tiny pieces(great fun it was too) while a 5.56 NATO will not.

Looks like someone forgot to take his meds again

The 556 is ideal for the urban environment. If cinder block destruction is how combat effectiveness is evaluated, then the 50 bmg is the best urban weapon in the military right? Clearing houses or ally's with an AR-10 is just silly, and posts like that waste my time having to respond, and other peoples time having to read them.

Urban, close quarter, and battle fields (like a jungle) with poor long range visibility are what the round was designed for....200 yards and in.

[jfruser]

Though the log burden is complex for two cartridges, I do not think a one-cartridge-for-all is really the way to go. I think that the rifle platoon's magazine fed rifles (general infantry, designated marksman, sniper) and belt fed SAWs & MMGs still would really require two cartridges. At the moment, those are 5.56NATO & 7.62NATO.

OTOH, I think that one _diameter_ of cartridge could be optimal: 6.5mm

Infantry could improve longer range performance, terminal performance, and penetration with a 6.5Grendel-like cartridge (fits AR15 envelope and/or AR15 weight class rifles/carbines). Downside is more mass for same number of rounds.

DM rifle and SAW would be a heap more effective with a 6.5G-ish cartridge and could really reap the benefit of 6.5G-ish trajectories. This here is where we would see the greatest gains that reap the greatest benefit from going to 6.5G-ish, as DM rifles and SAWs are designed to shoot at longer ranges than the basic infantry rifle.

Sniper rifle and MMG could also improve long range effectiveness by going to a 6.5Creedmore or .260Rem or some similar development, as those cartridges beat 7.62mmNATO at extended ranges. And their load-out would be lighter than were they toting 7.62mmNATO. Probably not enough mass savings (across the platoon) to offset the 5.56mmNATO to 6.5G-ish switch, but it makes the whole switchover a bit more reasonable.

This could be done with rebarreling existing weapon systems. Given how shot out many of the systems' barrels are, this is a simple and cost-effective way to do the cartridge switchover and extend the life of existing weapon systems.

Anyways, that's my $0.02.

[marine6680]

Why would they even bother with a rifle in 7.62? No need... The 5.56 is fine, and the new 885A1 round should help a good bit with effectiveness. There are much better designs that 7.62, especially if you design from scratch.

Engagement distances are usually under 300yds, and I believe it's typically under 150 or 200 for the majority... Extended engagement past 300yds is less common, though current conflicts have it happening a bit more often...

Usually the limiting factor is the individual using the rifle, rather than the caliber. So it's more a practical limitation with most engagements. Also psychological as well, as it was found that soldiers would wait for an enemy to get closer to engage, even if they had surprise at their disposal, and clear lines of sight.

Most infantry are not crack shots, with hit probability past 300yds declining fast... Which is exacerbated in actual combat. So needing a long carrying cartridge is completely unnecessary.


If you look at realistic needs of a general issue carbine... You will find that smaller and lighter rounds (within reason) work very well.

The current loadings used by the military fit those needs pretty well right now.

Bumping up to a 6mm, with a little more weight might work as well, but not enough to matter, not using the limitations of the current platform, namely cartridge length. You need a major change to try to combine more effective features into a round.

But do we really want a do it all round, that only does it mediocre?

Maybe if we develop new ammo tech it will work better to try for a single general purpose caliber.

A 6.5mm with not much more recoil, and similar final cartridge weight as current 5.56 ammo... And can manage to carry usable energy out to 500yds, and maintain good performance in barriers and some armor... May be a good general purpose rounds...

I doubt that could be designed and implemented in the next couple decades.

We may be able to do something if we compromise on some desirable features, like similar weight as current ammo...

But I doubt you will find a round that can reach out to 700yds or so, while maintaining reasonable recoil, low weight of ammo, and low weight of rifle, and that works well from 0yds out to the 700yds range for armor, soft tissue, and barriers...

Having two rounds would probably be best... A general purpose infantry round, and a DMR/SPR round.


If I was to throw in my speciation on a good general purpose round for infantry use...

I would say a 6mm in the 90-100gr range, with a velocity the same as current 77gr 5.56 2600-2700fps from a 14.5in barrel... With bullet construction similar to the 855A1... Recoil would be only a bit more than current offerings, and it would have some extra mass for barrier performance. Not sure if light armor performance would be better or not though.

For a DMR I would think a 6.5mm in the 125gr range pushing a velocity around 2900fps or a bit more from an 18in barrel, should carry well out to 600-700yds, with lighter recoil than 308.