While all the big bullet Bear hunters on this thread can no doubt master all aspects of shooting full power rifles in belted magnum calibers at 800 yards and beyond, the only thing that matters is CAN THE TROOPS HIT WITH THE RIFLE??? The answer, with the M14, was NOT USUALLY. With more training, a few strong and dedicated shooters will emerge as marksman, having mastered the skills necessary to engage small targets at extended range with big recoil and reduced inherent accuracy.
Or, you can start with 5.56mm, and EVERYBODY can shoot reasonably well, even the skinny guys and my goodness, the GIRLS!
Would you rather have 10 Marines that can enage targets to 1000m with the mighty M14, and 490 that can't shoot it past 10ft and hit anything , or 400 Marines that can engage targets to 500m with the M16, and 100 that can shoot it competently to 200m?
The issue surrounding service rifles and calibers are usually NOT related to "which is the best rifle for SGT York" - but which is best for the majority of soldiers, and to paraphrase the pistol shooters, a hit with a 5.56 is a lot better than a loud miss with a 7.62.
"MORE TRAINING" is not the answer, either. Training resources are limited, and the bottom line is you get more hits for your training dollar with 5.56 than with 7.62.
We are no longer a nation of riflemen.
Can't argue with you here. Anyone who's been watching that real-life US Army 'Boot Camp' show on the History channel should know immediately that a 7.62x51 rifle is just too much gun for the dorks and dweebs that the Army is recruiting and calling a 'soldier' after eight weeks. The M-14 is a fine rifle for riflemen, though -- namely, Marines. No, we're not going back; I agree entirely.
I also think that most of these 'what's the proper caliber?' discussions also blur the distinction between the military and civilian riflemen.
Civilian riflemen need accuracy and power at long range first and foremost. That's nearly a bygone in the US military.