I strongly disagree with every one that says .308 Win/7.62mm NATO is "too powerful" for a light full-automatic rifle. Most people say this based on the M14 and to a lesser extent the FAL. The AR-10 in full auto is a very different beast. The same goes for the FG-42. Both of these are quite "controllable" at 9.5 to 10 pounds. And, other than barrel heating problems with both would be okay in the squad automatic rifle role. It also, to some degree, is based on unrealistic expectations. Are you expecting the same accuracy standing off-hand in full-auto as you get in semi-auto? Are you expecting all the bullets to hit a man-sized target at 300 yards?