; (3) in subsection (d)(1), by striking or (k) and inserting (k), (aa)(2), (aa)(3), (aa)(5), or (aa)(6) ; (4) in subsection (e)(1), by inserting through the possession of a functional firearm before and has three ; and (5) by adding at the end the following: (q) A person who violates section 922(aa)(4) shall— (1) in the case of the first violation by the person, be fined under this title, imprisoned not more than 1 year, or both; or (2) in the case of any subsequent violation by the person, be fined under this title, imprisoned not more than 5 years, or both. . 4. Modernization of the prohibition on undetectable firearms Section 922(p) of title 18, United States Code, is amended— (1) in paragraph (1)— (A) in the matter preceding subparagraph (A), by striking any firearm ; (B) by amending subparagraph (A) to read as follows: (A) an undetectable firearm; or ; and (C) in subparagraph (B), by striking any major component of which, when subjected to inspection by the types of x-ray machines commonly used at airports, does not generate and inserting the following: a major component of a firearm which, if subjected to inspection by the types of detection devices commonly used at airports for security screening, would not generate ; (2) in paragraph (2)— (A) by amending subparagraph (A) to read as follows: (A) the term undetectable firearm means a firearm, as defined in section 921(a)(3)(A), of which no major component is wholly made of detectable material; ; (B) by striking subparagraph (B) and inserting the following: (B) the term major component , with respect to a firearm— (i) means the slide or cylinder or the frame or receiver of the firearm; and (ii) in the case of a rifle or shotgun, includes the barrel of the firearm; and