re: Why do civilians own "assault weapons"?

"Assault weapons" are defined by the military not common law definition. DOD--Assault is the climax of an attack, closing with the enemy in hand to hand fighting.COMMON LAW--Assault is an intentional act by one person that creates an apprehension in another of an immense harmful or offensive act. In common law, assault can encompass any imaginable weapon, pencil, fist, etc. In the military, it is a part of a battle scenario. Little bit different, don't you think? So, I guess your question has merit, in the civilian world.