FMJ yaw and upset performance

[Tony Williams]

Remember also that Tony is searching for a universal infantry cartridge to replace both the 5.56 and the 7.62 in infantry roles up to and including the GPMG. He has it right that the 6.5 120+ grain class of bullet is the minimum likely to be seen as a viable 7.62 replacement for the GPMG. Problem is that it stresses the assault rifle role and we still have the vehicle and aircraft-borne 7.62 inventory. The vehicle and aircraft-borne weapons community, given a choice, would likely opt for retaining the 7.62 but enhancing the ammunition.

Yes, that sums it up well, but I'd make a few additional points:

1. The 5.56mm is an unreliable performer (in terms of penetration and terminal effectiveness) even at short ranges, so a bigger and more powerful round would be desirable even if there were no call for a significantly longer range. This is what led to the 6.8mm Rem. So any "ideal" assault rifle round would have more ammo weight and recoil, by definition.

2. The recoil of a rifle with an intermediate round in the 1,800-1,900 ft/lb energy zone (probably the minimum for a "universal" cartridge) doesn't feel much worse than 5.56mm, and feels a lot less than 7.62mm. I say this after firing HK416, HK416/6.8 and HK417 in quick succession. So it should still be controllable in burst fire if needed in a short range emergency.