NFA'34 says that any pistol with a rifled barrel shall not be considered a short-barreled shotgun, which is why something thing like the Judge is considered a pistol despite firing a .410 shot shell. The NFA'34 does not state that all firearms with smooth bores are shotguns. Something like the Judge, which can accept either a .44 Long Colt or a .410 shot shell would be called a shotgun if it didn't have a rifled barrel, but there would be no basis for applying such a label to a firearm that's designed to accept a common pistol cartridge and does not accept any shot cartridge which is not designed for use in a pistol. Incidentally, if the Liberator is a short-barreled shotgun, so would be a typical carbine with a 16.1" barrel. The language which exempts rifled-barrel handguns from being called short-barreled shotguns does not exempt rifled-barrel shoulder-fired weapons. And just about any carbine can fire shot shells.
***...which can accept either a .44 Long Colt or a .410 shot shell would be called a shotgun if it didn’t have a rifled barrel,...***
Back in the late 1900s the Wild West Shows would order smooth bore colt .45s for use in the show. That way Buffalo Bill could shoot sand out of them and make it look like he was hitting a balloon or other item without endangering the audience.
But then, that was before 1932.
It’s my understanding that the “Judge” IS rifled - at least part way, sufficiently to dodge the law and classify it as a “pistol” rather than a “short barrel shot gun”.
Back in the depression days some fellas used to ream out the rifling in the barrel of a 1917 .45 Army revolver and use it against rattlesnakes. Along came the Feds and they were verbotten.
Most reasonable men will take their chances with a rattler before crossing a BATFE Nazi.
Of course you can fire shot out of a rifled barrel, but it tends to spin the shot column and project a “donut” pattern with a hole in the middle - right where you’re aiming.
I have excellent results however with a .22 pistol using #12 shot cartriges on rats, mice, snakes and such varmints fairly close in.
Check with the ATF web site http://www.atf.treas.gov/ about the “Liberator” - I’m pretty sure that it is considered a SBSG.
Back in the 1950s urban delinquents made zip guns out of cut off car antennae and a piece of hack saw blade. Just the right size for a .22. Obviously they were not overly concerned with federal regulations; most criminals aren’t. They know that the firearms charges are the first to get plea bargained away.
It’s usually the peaceable working stiff Peasant who gets thrown under the dungeon for possessing contraband you know.
Most firearms laws are patently absurd and tyrannical to begin with, but none of our politicians have the gonads to even try to reform any of them, and I’m not holding my breath for any to try any time soon.