danb
dont be a dumbass
If you have all the parts for a rifle, and all the parts for a pistol, how do you get around the constructive possession issue? How do you prove which one you built first? Its not like ARs are tricky to disassemble?
I only depends on what you bought the lower as, not what your intentions or if you have parts on hand.
If you transfer the lower to you as a rifle, then it is a rifle. To build it into pistol, you have to transfer it as "Other" on your 4473 item 16.