I've seen the videos. I'll take an AR/M16 first, and for full auto, give me a rifle that can hit the same county more than once. Having said that, I've built up two AK47s, and they both are fine for the first shot. After that, the accuracy falls off in rapid fire. The 5.56 is accurate, but the 7.62x39 will go through stuff the 5.56 will not. More ammo with less weight with 5.56, more pounding with the 7.62.
So, what's the mission?
Apples and oranges.
Heck, for CQB, give me a shotgun.
Jeff