To possess an "Assault Rifle" in the US you need to have a Type 6 or Type 7 Federal Firearms License. You have to apply to the ATF and the State Department, wit

To possess an "Assault Rifle" in the US you need to have a Type 6 or Type 7 Federal Firearms License. You have to apply to the ATF and the State Department, with a background investigation done by the FBI. You undergo yearly inspections of inventory and records by a federal or designated state agent. The location at which the firearm is stored must be approved at the federal, state, and county level. Pretty much the only people who bother to go through all this are the folks who manufature them for the military. What most people confusingly label "assault rifles", AR-15s, are not fully automatic or even select fire. Many states even ban you from hunting with them because the cartridges are too small to mortally wound animals with a single shot.