I don’t care much for the M-14. I was tained on the M-1 Garand. However, the one saving grace of the M-14 was that it fired a bullet capable of KILLING the enemy with one shot. 7.62 or 30.06 - don’t know much of the inherent, if any, differences to prefer one over the other. But both KILL. Isn’t that the primary characteristixc of a military weapon? Or do we design a weapon that harmlessly captures rather than harms the enemy?
I think the idea behind the smaller caliber is that it’s designed to maim, rather than kill. The theory is that a wounded soldier is more of a liability on the battlefield than a dead one. He can’t fight effectively, and he’ll slow everyone else down. A dead soldier just gets left behind. FWIW.