Army announced winning design for the 6.8mm cartridge

I looked through the previous topics. Was some discussion a bit back. The Army has choose a new cartridge based on the 6.8mm. That is the first step in selecting a new rifle (except for the M1 Garand, all new rifles were preceded by a new cartridge).

True Velocity was awarded the design. TV has a number of polymer cartridges on the market. From 5.56x45 to .50 caliber. It makes sense to go to a polymer case as we do not need to leave brass on the battlefield and the military does not reload.


Welcome to the Forum.

True Velocity used some deceptive wording in their press release. The 6.8mm TV polymer cartridge has NOT been selected as THE cartridge of choice. But General Dynamics/True Velocity were chosen as one of 3 weapon/cartridges designs to participate in the next phase of NGSW (Next Generation Squad Weapon) systems development.

General Dynamics/True Velocity is in completion with SIG (6.8x51mm composite case) and AAI Corporation Textron Systems/ H&K /Olin Winchester 6.8mm Cased Telescoping Ammunition (CTA)


I’ve been watching the outcome of this programme eagerly for many months, and there has been some fascinating new ammunition and weapon designs.
I wonder if this is being watched and possibly considered by the British MoD. With the ageing L85 series of assault rifles being replaced after 2025, it seems more logical to me to upgrade to a new ‘future proof’ design instead of another 5.56.

Best regards,


I’ve been out of direct touch with British Army thinking for a couple of years now, but the last I heard they were not just watching, they were actively involved in the US Army’s work in this field. I think it is almost certain that they will buy whatever the US chooses (assuming that they do manage to choose something and actually adopt it, this time).

Not just the cartridge, but the weapon platform too must be of interest to the UK given our lack of domestic capacity for producing small arms … a long-term problem dating back over 50 years, these are skills that can’t just be conjured up out of thin air and the SA80/L85 is hardly a happy precendent.

But then we’ve hardy got enough troops to make an independent design worthwhile.

It’ll be interesting to see how this process works out.


O yes, Peter, that’s what I meant. It is clear that the new ammunition will require new guns; they come as a package. This is most obvious in the case of the cased-telescoped ammunition by Textron, but also applies to the more conventional pair. The metal-cased SIG cartridge has similar overall dimensions to the 7.62x51 but runs at 80,000+ psi instead of around 50-55,000 psi, so you can’t just convert existing guns to fire it - the action needs to be much stronger. The TV ammo plus GD-OTS guns also work together: in this case, they seem to have reduced the pressure by adopting a longer barrel, and (in the case of the carbine) kept the weapon length down by adopting a bullpup configuration.

Apart from precision sniper rifles, the UK lost the ability to develop small arms long ago. I agree that it would make no sense to set up a factory just for a couple of years to make a relatively small number of weapons in the UK, they will almost certainly be MOTS purchases (Military Off-the-Shelf).

I believe that the new round will be called the 6.8 GPC (general purpose cartridge).

Anthony Williams is a well know UK writer on military small arms.

Hello Greg, Anthony Williams is the same Tony Williams that has posted above.

Tony is one of my favorite authors and writers. I used to follow him on 6.5 Grendel forum.

It appears that the 6.5mm might be sidelined with the Army pushing the 6.8 GPC

Gentlemen, you are at serious risk of embarrassing me…

Tony - don’t be embarrassed by the truth!


Tony in your opinion what do you make of the three competitors for the NGSW? You were the one who showed that we have two cartridges and four weapon systems and needed to bring that down to one cartridge, an Infantry rifle and a SAW/IAR.

Sig seems to have an edge but TV has a better cartridge design.

This is a difficult one. My own suggestion for a General Purpose Cartridge (GPC) as developed in detail HERE concerned one which could replace both the 5.56 mm and 7.62 mm NATO rounds with one intermediate in power between the two of around 6.5 mm or 6.8 mm calibre, using relatively low-drag bullets to deliver long-range performance to at least match 7.62 mm, while having significantly less weight and recoil than that cartridge.

To put some numbers on that: the 5.56 mm develops around 1,700 J muzzle energy, the 7.62 mm some 3,400 J, and my GPC around 2,500 J.

I should maybe emphasise that the 6.8 mm Rem SPC is less powerful than my GPC and handicapped by only having room to fit short, high-drag bullets, harming long-range performance, so it cannot be a GPC. The 6.5 mm Grendel is better, although still not quite powerful enough IMO.

The .264 and .277 USA (6.5 mm and 6.8 mm respectively) developed by the US Army Marksmanship Unit (USAMU) several years ago initially matched my proposals quite closely. However, they subsequently uploaded the case to improve the performance, at the cost of more recoil and less controllability in burst rifle fire.

More recently, the Army has changed its ammunition performance requirements to include the ability to penetrate modern military-grade body armour at normal combat distances. This requires a lot more power than my GPC, with a muzzle energy significantly higher than even 7.62 mm - in the region of 4,000 J. In 6.8 mm calibre as specified by the Army, this is really in the magnum class.

To make matters worse, the Army not only wants to use this in MGs, but also in compact carbines. In conventional weapons, that means a short barrel, and the shorter the barrel, the higher the chamber pressure needs to be to achieve any given muzzle velocity. So all three competing cartridges are apparently running much higher pressures than existing military ammunition. There are obviously risks in this approach, and high pressures mean greater barrel heating and wear as well as more risk of things breaking.

I personally like the GD-OTS weapons using the TV ammo, for three reasons:

  1. The compact bullpup carbine layout permits a long barrel in a short gun (there’s about an 8 inch length saving over a conventional rifle), also helpful because of the requirement to use a suppressor, which adds more weight and length.

  2. The longer barrel means that the pressure can be lower for the same performance.

  3. The polymer case has an insulating effect, so the chamber will not heat up so quickly and cook-offs are difficult to achieve. There is also a greater weight saving than the metal-cased SIG. Of course, that assumes that the polymer is able to meet exacting military standards.

However, none of these cartridges is really a GPC in my opinion; if the Army does adopt one of them, it would probably only be issued to front-line infantry whose primary weapon is the rifle. There would still be a need for something much smaller, lighter and handier for all other troops, so the 5.56 mm M4 would probably remain in service (in much larger numbers than the 6.8 mm) for the foreseeable future.

The Army is referring to the 6.8 round as being a General Purpose Round.

here is an article from last year on the NGSW

In a case such as this it’s always interesting to see where potential adversaries are heading … are the future plans of both Russia and China for replacing their infantry small-arms known ?


Peter, Russia has tested / is testing the 6.7x51:

6.7x51_OTs-123 sniper rifle_OTs-124 MG_Russia

the last picture is not a 7.62x51 necked down to 6.7mm ?

It appears to be!