“Pistol Grip Firearms”
Pistol Grip Firearms (PGF), or “pistol grip only” firearms as they are sometimes called, are another category of non-shotgun “shotguns.” This category includes firearms that have a smooth barrel, are more than 26 inches in overall length, but don’t have a buttstock and therefore can’t be shotguns. They aren’t really handguns either. Instead, the ATF has created this middle-ground category for firearms that are long enough to be a shotgun but don’t have buttstocks.
The good news is that PGFs, unlike AOWs, are standard firearms that don’t have all of the extra restrictions of NFA firearms. This is true even if the PGF has a barrel shorter than 18 inches as long as the overall length is over 26 inches. It can’t be an SBS because, without a buttstock, it isn’t a shotgun. And, because it is over 26 inches, it isn’t a handgun nor is it “readily concealable” so it isn’t an AOW.
It can be tricky to make your own PGF at home – especially if you intend to have a PGF with a barrel length under 18 inches. In order for a PGF with a barrel shorter than 18 inches to be legal, it must have been assembled from a receiver that never had a buttstock attached and it must still be longer than 26 inches in overall length. If the firearm receiver was ever assembled with a buttstock then it was a shotgun at some point and the short barrel would create an SBS, even if the overall length was over 26 inches. Instead, your best bet is to purchase one of Mossberg’s 500 or 590 PGFs that come from the factory without buttstocks.