Quote Originally Posted by PanzerJaeger View Post
5.56, particularly in its original American 55gr M193 form, actually causes far more damage to the human body within normal combat ranges than 7.62 due to fragmentation. Not so, however, with the current 62gr rounds being fired out of such short barrels. The US had a very potent weapon in the original M16, but has neutered it quite a bit over the years.
The major advantage of the 7.62 was range - and as noted the M-16 has had it's wings clipped for valid reasons.

Any enemy, even the most ruthless, has to expend more time on a wounded soldier than a dead one.

Aside from that - 5.56 allows for more ammo but does tend to jamm more in icy conditions for reasons I'm not clear on.