assault weapons have their place in the hands of citizens and they have a place in the world of responsible self defense. dont say that there is no reason to have an assault style rifle unless you plan on doing harm with it. there are plenty of applications where a handgun or shotgun is just insufficient and the wrong tool for the job. not to mention there are plenty of people who just own an assault rifle because they shoot for sport and for the fun of it.
it takes anywhere from 4 to 6 well placed hit to stop a determined threat (excluding shots to the head). add drugs to the equation and that number can double. add two threats to the equation and now that number has doubled again. but of course everyone is a professional speed reloader and keeps plenty of magazines at hand

not to mention that a .223 round is actually safer to discharge inside of a house than most common handgun rounds. dont believe me, then look at the ballistic tests on different calibers invloving drywall