"I believe in tests the M-16 with their ballistic pattern and "kill ratio" were similar to the 7.62m. Higher speed (FPS)of the M-16 round helped with the internal damage."
The text book theory's alwayhs sound good, but in actuallity the 5.56 is not what it is all cracked up to be. The military guys in Afganastan and Iraq are wanting M14's and the US is (unbenounced to many), frevorishly reconditioning and producing as many M14's as they possibly can. Just try to go buy a new M14/M1A from Fulton Armory or any other company ... you'll be waiting a good long time, but you can ge an AR15 at the drop of a hat.
The real problem boils down to marksmenship. In WWI the "Doughboys" could drop Germans with their 03's from 800 yrds!! One shot one kill was a consept long before the snipers took it over. The tradition of riflemen in America has been almost lost. If marksmenship was a major virtue, then weight would not be such a factor since it would take a soldier only 1 or 2 shots to dispatch an enemy combatent instade of spraying 30, 40, or 50 rounds of the small stuff.
" However, I do know that I would rather carry the pig (M-60) over the M-249"
The M-60 has been replaced by the M-240G as our Medium Machine Gun. The M-249 still is what it has always has been; the Squad Automatic Weapon (it is as it's always been a POS). The 240G is a reliable machine gun, though a little heavier than the 60, and still chambered in 7.62