Grendel as a Universal Infantry Cartridge

[Tony Williams]

And the SPC guys are getting close with 6.8x43 loaded with long-ogive bullets, although it sounds like chamber pressure may be on the high side. Also, they are talking about making a "stretched" 6.8x46, a la Tony Williams' proposal.

My thinking on this subject has been gradually evolving. I'm now inclined to think that while 6.8x46 may be about right, the case diameter should be wider than the 6.8x43, for two reasons: the need to accommodate significantly longer copper+steel bullets, especially tracers, which will occupy more of the case capacity; and the desirability of allowing for the future use of part-polymer cases, which may have thicker walls than metal ones, thereby further reducing propellant capacity.

I think it is essential for the success of the concept that soldiers using the new round in combat must not notice any shortfall in comparison with the 7.62mm, especially in long-range hit probability, otherwise they will still insist on keeping the 7.62mm. If the new round can provide this while achieving significant reductions in weight and recoil, then I think it could kill off the 5.56mm, given that many soldiers have said that they would rather carry 7.62mm weapons than 5.56mm.