Very true. I do forget at times that while I can reload an AR almost as fast as I can shoot it, someone else may not be able to reload in the time it takes to rush them. But a .223 goes a long ways. Again, I point that the nutjob in Portland, had the 100 rd magazine. It jammed(a common failing with large capacity magazines), and he didn't have another magazine to swap.
The thing that worries me though. THIS
They are out there. And will continue to be out there even after the ban.