One of the things that the NGSW is looking to enhance is the individual shot lethality of the combat rifle, and now that we know a little more about the program is seems that the new 6.8mm rounds are looking to springboard off earlier developments… specifically in 5.56 with the M855A1.
The 5.56 EPR and 7.62 EPR rounds, M855A1 and M80A1 respectively, have a projectile design that does two things. One, and probably the most publicized aspect, was it was a “green” round that didn’t use a lead projectile. Environmentally friendly lethality. The second and more important aspect was being a more accurate, consistent, and terminally effective round.
Both A1’s accomplish this by upping the pressure, and thus the velocity, of the rounds are at the high end of their safe pressure spectrum. The projectile’s tips are hardened steel and that, combined with the increase in speed, give it very good penetrative capabilities.
The new 6.8mm, in all three submissions, have high velocity, energy, and penetrative capabilities, greater than those of 5.56 and 7.62 rounds. The greatest limitation of current weapons is the physical limits of their calibers. We’ve pretty much optimized what we can do with 5.56 rifles and it’s pretty good. To jump the weapons capabilities we need to change calibers. The 6.8 solutions are designed to use that same maximization concept, but without the old limitations of a 5.56 case or rifle interior loading limitations.
Building around a projectile and to meet a velocity requirement allowed Sig, Textron, and General Dynamics a wider methodology to solve the equation. Of the three, I think Sig’s makes the simplest and most likely candidate for success. A fairly conventional case but formed in a way to maximize its capacity for powder and then placed within a variant of its well liked MCX Chassis in a “.308” length action.
The result, an updated carbine and automatic rifle/machine gun that closely resembles what the M4 feels like, runs like, and weighs, while increasing the effective range closer to a kilometer, or perhaps beyond. Also giving it an increased range envelope for armor defeat.
Science. Ballistics. Effective range on targets based on hit percentage. Effective range against armor. It’s a fun topic.