Last definition that Clinton signed.
Semi-automatic rifles able to accept detachable magazines and two or more of the following:
Semi-automatic pistols with detachable magazines and two or more of the following:
- Magazine that attaches outside the pistol grip
- Threaded barrel to attach barrel extender, flash suppressor, handgrip, or suppressor
- Barrel shroud that can be used as a hand-hold
- Unloaded weight of 50 oz (1.4 kg) or more
- A semi-automatic version of a fully automatic firearm.
Semi-automatic shotguns with two or more of the following:
- Folding or telescoping stock
- Pistol grip
- Fixed capacity of more than 5 rounds
- Detachable magazine.
Notice this list excludes most of the guns people today are referring to as assault weapons.