I am thinking of a shotgun originally designed as one not intended to be fired from the shoulder, not a converted one.
I agree with you in that it might be possible to purchase only a shotgun receiver.
Going back to the original question, I broke down the federal definition below. Are firearms, which are chambered for shotgun shells, still considered a shotgun if they have rifled bores, rather than smooth bores? Along the same lines, what if these firearms are not intended to be fired from the shoulder, and they have rifled bores, are they still considered shotguns?
The term “shotgun” means:
- a weapon designed or redesigned, made or remade, and intended to be fired from the shoulder, AND
- designed or redesigned and made or remade
- to use the energy of the explosive in a fixed shotgun shell
- to fire through a smooth bore
- either a number of projectiles (ball shot) or a single projectile
- for each pull of the trigger, AND
- shall include any such weapon which may be readily restored to fire a fixed shotgun shell.