I've heard it both ways as well hence the question.I think the point of the OP, was the cannelure.
So the question becomes, do you need to use bullets with a cannelure in an AR?
Personally I've heard it both ways. In a LGS a guy who shoots/reloads a lot says he's never used bullets w/cannelure and never had a problem.
I go to another LGS and their reloading guy says YES! In fact he has blown AR's out back as a result of shooting non-cannelure ammo that have suffered bullet jump.
Me? I use cannelure ammo. 1) Better safe than sorry 2) Uncle Sam & NATO use cannelures and I *think* they know more than I do.