Pie In The Sky 6.8x51mm Composite Case Ammo for US Army Next Generation Squad Weapons Program Prototype


A friend sent me a link to a SSD article about the ongoing attempt to replace the 5.56MM and M4/M16. A soon-to-be cancelled program with the Xiden budget cuts sure to come. Let’s take a look at the propaganda.

Last month SIG Ammunition delivered 825,000 rounds of their composite cased 6.8x51mm ammunition to the US Army for Prototype Test #2 of the Next Generation Squad Weapons program.

The NGSW program will replace the 5.56mm M4 Carbine and M249 Squad Automatic Weapon with a new Rifle and Automatic Rifle at the squad level in close combat formations like infantry and cavalry scouts. Will it though? Will it? The other services are monitoring the program as well to decide if they want to participate.

At the heart of this program is the ammunition. The Army gave industry a 6.8mm projectile and a performance specification, but left it up to them on how to best deliver that projectile within the required performance parameters.

Turns out, that performance they are seeking is similar to 270 Win Short Mag. The velocities required to achieve the desired effects for that 6.8mm projectile on target call for extremely high chamber pressures in excess of 80,000 psi; previously unheard of for small arms. Yes, and there is a reason for that, but not that this company man would know that.

As if it wasn’t enough that the ammunition is a larger caliber than what it is replacing, it has to be at least 20% lighter as well. The SIG ammunition hybrid design beats that goal at 23.5% lighter than the weight of an equivalent energy cartridge (270 WSM). Below, you can see the hybrid case next to conventional all brass cased ammunition.

This is no science project. The Army plans to pick a solution by next year. While the engineering alone is daunting, industry has to also be able to actually manufacture the ammunition and weapons they’ve designed, in the event they are selected. Good luck with that.

NGSW Candidates

The requirement has led to some interesting solutions. From an opening crowd of 16 industry teams offering various solutions, the Army narrowed it down to just three: SIG SAUER with their own hybrid cased ammunition consisting of brass body and steel head; General Dynamics-OTS teamed with True Velocity to introduce a recyclable polymer cased cartridge; and Textron Systems using a Case Telescoped cartridge which features a polymer case that completely encases the projectile and propellant, resembling a rimless shotgun shell. This slide depicts all of the candidate systems.

You can read the rest of this pure piece of propaganda from SIG below.


  1. Said it before, And proof of concepts or test beds. sure. I think it’s good to always be pushing boundaries and doing R&D. But replacing everything? Come on.

  2. I suspect the .308 backwards compatibility of the Sig offerings is by design. Remember the ICSR abortion? This is that project rebranded. Case in point, the specs for .277 FURY are a 130 grain round at 3000 fps from a 13″ barrel. M80A1 EPR is a 130 grain round at 2900 fps from a 14.5″ barrel…

    1st World Joes can’t shoot accurately past 300 yards on a good day, so a battle rifle cartridge would be wasted in their hands. Volume wins wars, not marksmanship. More effective than any infantry rifle caliber against body armor is direct explosive overpressure, which is criminally under-used due to unintelligent rules of engagement that none of America’s enemies follow.


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