Ab_Normal
Ab_member
Are you saying the additional 20 percent is the converted part?
No. I'm saying the law as written does not consider even 100% receivers as firearms until they are configured to be able to expel a projectile.
Remember it has to meet the requirements of A before it can be considered for B.
18 U.S. Code § 921 - Definitions
(3) The term “firearm” means
(A) 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;
(B) the frame or receiver of any such weapon;
YMMV