Privately made firearm

Privately made firearm (PMF). A firearm, including a frame or receiver, completed, assembled, or otherwise produced by a person other than a licensed manufacturer, and without a serial number placed by a licensed manufacturer at the time the firearm was produced. The term shall not include a firearm identified and registered in the National Firearms Registration and Transfer Record pursuant to chapter 53, title 26, United States Code, or any firearm manufactured or made before October 22, 1968 (unless remanufactured or remade after that date).

Source

27 CFR § 478.11

Scoping language

When used in this part and in forms prescribed under this part, where not otherwise distinctly expressed or manifestly incompatible with the intent thereof, terms shall have the meanings ascribed in this subpart. Words in the plural form shall include the singular, and vice versa, and words importing the masculine gender shall include the feminine. The terms includes and including do not exclude other things not enumerated which are in the same general class or are otherwise within the scope thereof.