The joys of bureaucracy...
-- If it was a rifle, and duly noted 'rifle' on the 4473, it can never be anything but a rifle. Although the receiver of which in no means differs from a pistol of the same frame, aside from being duly noted as such on the 4473.
-- If it was a pistol, and duly noted 'pistol' on the 4473, it can be made a rifle, but then supposedly never made a pistol again. But, unless subsequent 4473 was filed on it, as a rifle, how is ATF to know it has ever been anything but a pistol?
-- If it was a stripped receiver, and duly noted 'other' on the 4473, it can be made either a pistol or a rifle. However, if made a rifle it can never be made a pistol, but if made a pistol it can be made a rifle, wherein it can never be made a pistol again, if it's ever been duly noted a rifle on subsequent filing of 4473, however if it hasn't been noted otherwise how is ATF to know? Unless of course you are not 21 years of age, wherein the pistol option is out the window to begin with, it can only be made a rifle, and duly noted as such on the 4473, wherein it can never be made a pistol.
All of which is as damned ridiculous as
their most recent ruling on arm braces for AR Pistols, which states that if you are shooting an AR Pistol with an armbrace on it, and raise that brace to your shoulder, it then somehow magically transforms that pistol into a short barreled rifle and as such requires proper forms be filed for possession thereof, however if you don't raise it to your shoulder, it is then still legal to possess the same exact weapon without filing the aforementioned required forms. That ruling however wasn't specific as to whether or not the AR Pistol with arm brace could ever be made a pistol again, once being magically transformed into a short barreled rifle. And, begs several questions...
-- If I remove the brace from my shoulder does it magically become a pistol again? If not...
-- How long must the brace be removed from one's shoulder before the weapon again becomes a pistol?
-- If I use the brace as intended, and my cousin shoulders the weapon, does it become a rifle for both of us, or is it only a rifle for him?
-- If I buy a used AR Pistol, how am I to know if anyone has ever had a brace on it and shouldered it, wherein it was magically transformed into a rifle, wherein I can't legally own it without filing paperwork although it technically is still duly noted pistol on the 4473.
-- If it becomes a rifle because I shouldered the brace, and I remove the brace, wherein it cannot be shouldered again, and it is duly noted a pistol on the 4473, is it then mystically still a short barreled rifle, or is it technically a pistol because it has never technically had a shoulder stock and rifle buffer mounted and is duly noted pistol on the 4473.
All of which begs the question... If you buy a Used AR how do you dertermine if it's had a sex change operation, physically, mystically, or technically???
And, do those morons lay awake nights dreaming up these ridiculous rules???