I used the M16A1 in Boot Camp, then transitioned to the M16A2 in the Fleet. I have only seen/used M14's in Formal Drill Squads.
Of course, the M60 Machine Gun is 7.62.
Of course, the M60 Machine Gun is 7.62.
I normally only think of the M249 which is 5.56 but yeah, the M60E3/4 is a 7.62. Having had a chance to fire an AR15 and an HK SR9 I will say that the 7.62 kicks like hell and the rifle is significantly heavier. Wouldn't want to have to one in a ready fire position for that long.