This is from the ATF website:
Gun Control Act Definitions
Define: Firearm
Defined Under: 18 U.S.C., § 921(a)(3)
This section is intended to provide basic guidance in understanding firearm terminology. Please bear in mind that these illustrations do not necessarily depict importable firearms.
The term “Firearm” means:
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;
--- This is per the ATF
Gun Control Act Definitions
Define: Firearm
Defined Under: 18 U.S.C., § 921(a)(3)
This section is intended to provide basic guidance in understanding firearm terminology. Please bear in mind that these illustrations do not necessarily depict importable firearms.
The term “Firearm” means:
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;
C. Any firearm muffler or firearm silencer; or
D. Any destructive device.
Firearm Frame or Receiver
That part of a firearm which provides housing for the hammer, bolt or breechblock, and firing mechanism, and which is usually threaded at its forward portion to receive the barrel, is considered a firearm per 27 CFR § 478.11.
