Right, the 7.62mm NATO round survives in support weapons (M60/M240B/GPMG etc. and various sniper rifles) BECAUSE it has superior range and pentrating power (the same thing applies to .50 cal/12.7mm). Although Redneck states the case for a smaller service round for rifles and squad support weapons very consisely

, even upgrading to the higher power of the 5.56mm SS109 round for the M249 and M16A2 series rifles does not change that (more like admitting that the original 5.56mm round was underpowered

).
Changing to 7mm might fix most of this disconnect (.50cal/12.7mm will always be around although maybe not in the M2HB), but then again, it might not. So could somebody try so we can find out?