heh - ok. all good and i'll tell you my own thoughts on this and we can compare.
a ruger 10/22 rifle is a .22 rifle. about the most popular out there. it is referred to as a "semi-automatic" rifle in that it will hold 15 rounds (and you can buy larger capacity mags) and once you release the trigger, it will cycle and you can pull it again as it will load another into the chamber for you. pull the trigger and it will fire again until the mag is empty or you get tired of doing it.
a 9mm pistol can hold 8-16 rounds, give or take. same thing, however. it only fires as fast as you can release and pull again.
an AR/15 will fire usually a .223 / 5.53 or .308 round. they can hold 15+ rounds depending on the magazine. however, they fire no faster than the 10/22 or 9mm previously.
the "advantages" of the AT is that you can collapse it down for tighter quarters (in many but not all instances) and you can put things like laser sights on the black rails surrounding the barrel. however, it fires no faster.
a fully automatic gun can fire at different rates but just hold and it fires. you and i can't walk into a store and buy one of these. the odds of us ever owning one, highly remote and even trying will get you checked out in many ways you'd rather not be, regardless of spotless past or not.
so what about "these guns" make it a bad choice for someone vs. a semi-automatic deer rifle shooting a 30-06 or .308 also? what about these guns should be banned from "civilian" guns? which features?
in a close situation like that, several pistols and extra mags would have done the same thing. most people hate AR's and call them "assault rifles" but look up the definition of assault right and see how it's changed w/the agendas. used to be fully automatic but those are hard to come by so now they're the AR-15 and the like. so again, what would you ban from this style of gun to make it like a hunting or other rifle that would stop these kinds of shootings?
btw - no it wasn't a question, it was just incorrect. he did not have such a weapon that i've heard of yet, only store bought guns. you cannot buy a fully automatic weapon in a few days and esp with his history.