There really isn't much difference between an assault rifle and a semi-automatic rifle, pistol or shotgun. If you want to go crazy and kill a whole bunch of people, you can do it with a semi-auto or an auto, it doesn't really make that much difference. At a guess I'd probably say I could kill more people on semi-auto than fully automatic in a lot of situations. Indiscriminate fire really isn't as huge a deal as some will make out.