Rifles with folding or extendable stocks can be said that they are still "intended" to be shoulder fired. If no shoulder stock exists, it doesn't meet the definition of a rifle. I'm not quite sure what it would be under the law. Possibly a rifle illegally converted to a very large pistol??
It would still not meet the definition of "pistol".
We did this a while back in reference to the M2 semi automatic belt fed.
It's not a rifle since it was not intended to be fired from the shoulder, but it's not a handgun because of the length.
It's simply a "firearm".
I'm unable to find where it is illegal to convert a rifle to a "firearm".
It's illegal to make one into a pistol, or an SBR, (without tax stamps) but I can't see anywhere that it's illegal to simply make a "firearm".
(*) how PG-only shotguns get away with it, I don't know.
Same thing, it's a "firearm" but not a "handgun".
Definition of "firearm":
Firearm. Any weapon, including a
starter gun, which will or is designed to or
may readily be converted to expel a projectile
by the action of an explosive; the
frame or receiver of any such weapon; any
firearm muffler or firearm silencer; or any
destructive device; but the term shall not
include an antique firearm. In the case of a
licensed collector, the term shall mean
only curios and relics.
So, there are rifles, shotguns, handguns, and firearms.
On the NFA side there are SBS and SBR which have specific length definitions.
A rifle or shotgun without a shoulder stock, but longer than the NFA lengths, don't seem to fit into any definition other than "firearm".
Like this, a "firearm". Can't be a rifle, too long to be an NFA weapon. So, merely a "firearm".
So the question is then, is it legal to convert a "rifle" to a "firearm" or does it even matter?
I have never seen anything prohibiting that. You can't make a pistol, you can't make an SBR, but not a word about making a "firearm" out of a rifle.