It’s happening. A bit at a time, but happening.
Hit something (or some one) with the 7.62, it goes down and, (more importantly) STAYS down.
I agree. The people who were advocating the 5.56 always talked about the potential for wounding and how it would take two more men out of the battle to carry the wounded away from the front lines. In my experience in the desert, the guy that was wounded continued fighting.
In close quarters battle you might hit the guy several times with a burst and stop the fight, but at ranges out around 300-400 meters using iron sights you were lucky to hit him once. If he found out about it he would get really angry.
I understand that they're starting to see a lot more guys wearing body armor, too. I don't know that the 5.56 can penetrate body armor at 300 meters when fired out of the M-4.