Textron Systems NGSW Rifle and LMG

[BluntForceTrauma]

So a 6mm bullet would be better than 6.5 would be better than 6.8?

So it would seem — if armor penetration at distance drives the requirement and if one also wants to keep overall bulk down.

Here's a thought experiment: What would it take to drive a 6mm 110gr-bullet to a muzzle velocity of 3,000 fps?

110gr cuz let's assume tungsten or something dense wants to be used, in the worst case, for armor penetration.

Using an 80,000 psi chamber pressure, what is the overall length of the case and the diameter of the case head?

Using today's standard technology, the 6mm GT meets the above requirement with a 0.473 case head and 1.7" case length.

If the chamber pressure is increased like they're doing for NGSW, how much can the case shrink?