So, long guns are responsible for ~4% of gun deaths (including suicides), and "assault weapons" are a subset of that 4%. And your solution is to ban them? Fine. Shave a percentage point off.
But there's an elephant in the room. Why are we not talking about pistols? Going to need an answer on that one.
Funny note: Any European child can walk in the store and buy a suppressor. Had a German guy tell me on reddit that his gun range requires such devices. Not trying to change the subject, but maybe American gun laws are a bit out of whack? Or, more to the point, racist as fuck.