We’re not talking about shotguns in the purest, legal sense here. We’re talking about firearms. That’s because firearms that ignite shot shells that aren’t designed to be shouldered aren’t considered “shotguns” by the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). That’s why these firearms can have barrels shorter than 18 inches and not fall into the restricted NFA category. With that said, if we slip up now and then and use the word shotgun, it’s only intended to be descriptive of the ammo it consumes.