Textron Systems NGSW Rifle and LMG

[LRRPF52]

BTW, if you're wanting to go to 6.5mm to decrease cartridge bulk, that would not help significantly.

.277 - .264 = 0.013

Reduce the polymer case diameter by 0.013" and it'll still be at least as fat as the 7.62 NATO round.

The bulk also comes from the propellant volume required to push a heavy .277” projectile that is heavy in order to meet the BC required to retain enough energy for the terminal requirements at distance.

The 5.56 LSAT cases are much smaller.

I think a .243" or .257” high BC EPR projectile would be far more ideal than .277” for these reasons. It would lighten the overall system as well since the recoil force is substantially different. You don’t need as much chamber pressure to reach the same performance requirements, and have better sectional density for the armor-defeat metric.

This would also allow the rifle version to fit a smaller form factor, with 30rd mags, as opposed to these large mags required for the NGSW rifle variant.

Magazines have weight too, so when you cut round count in favor of performance, you increase the magazine count even for a lesser overall combat load, while also making it more difficult to store those magazines on load bearing kit.

Another major problem I see is that just as soon as something like this gets finalized and produced, the intended threat simply upgrades their body armor.

There are advancements in armor technology currently underway that threaten to make small arms even less effective.