The definition from the United States Defense Department, without looking it up and copy pasting is something like, a compact firearm with selective fire, and fires an intermediate power cartridge. the key word there being SELECTIVE fire, meaning semi AND automatic.
The other definition ive heard from military branches is that its a selective fire combat weapon used by military personnel.
the reason the term assult rifle even came into use was as a way to distinguish the military weapons from others. its between a pistol, and a large caliber rifle. the media adopted the term because it sounds scary. and now everyone thinks you can go out buy straight up rambo weapons and mow people down with a simple background check.
the previous assult weapons ban, and this new BS ban, both created by people who probably havent shot a gun in their life, and just want to enact it for the sake of "taking action" define it as a weapon that has 2 or more of some certain features, that basically make the gun more comfortable, or just look kinda scarry. so if your gun has a telescoping stock and flash suppressor(neither of which do shit) you now have a big scary "assult" rifle.
and yes there are laws against purchasing a selective fire assult rifle, it takes around 8 months of various pain in the ass checks, forms, fingerprints, etc.. as well as a shit load of money just for the gun itself. and i wonder how many of these legally obtained automatic rifles are used in crimes? im going to just assume around 0.
they are now saying the school shooter didnt have his AR with him, it was in his trunk, he had 4 pistols. so this whole "assult" rifle freak out started due to ignorance and making emotional decisions, people like to think with emotion before common sense and thats why this is such a big deal. it gave the government an excuse to take advantage of peoples emotions and take away more power while people cant think straight.
and another think i hate about the media, when a cop uses an "assult" rifle, the media calls it a "field use rifle" yet when somebodys shot with a NON assult rifle, they call it an assult rifle because it looks scary. and even worse, when they find a NON assult rifle in this kids trunk, not even used in the shooting, "assult" rifles become the enemy.
i wonder if any of the people for an assult weapons ban know who many rifles were involved in homicides last year VS stabbings? clubbing? being beaten to death? and how many of those rifles were legally obtained?