I don’t have much experience with firearms, but from reading what other FReepers have said through the years, the 5.56 round is certainly not high-powered.
Compared to a .50 cal or some hunting ammo no, but it is a high velocity round.
It is high powered enough, my Friend....
It's powerful enough, though, to let's say, "hurt very very much" out to about 400 yards or so, depending on which loading and the barrel length of the rifle shooting it, which makes it a cannon alongside any handgun cartridge.
(Well, any handgun cartridge a sane person would shoot, that it, up to and including the .44 magnum. No offense to some of the guys who shoot ubermagnums. You know who you are.)
I see you got some good answers about the relative power of the 5.56 cartridge but my point was ‘why aren’t they calling those ARs “assault weapons?” Do they become something different when the guy holding them has a badge?