1. Short title This Act may be cited as the Undetectable Firearms Modernization Act . 2. Modernization of the prohibition on undetectable firearms Section 922(p) of title 18, United States Code, is amended— (1) in paragraph (1)— (A) in subparagraph (A), by striking grips, stocks, and magazines and inserting all parts other than major components ; and (B) in subparagraph (B), by striking when subjected to inspection by the types of x-ray machines commonly used at airports, does not generate and inserting the following: 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 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 ; and (B) by striking subparagraph (C) and the proviso that follows and inserting the following: (C) the term Security Exemplar means an object, to be fabricated at the direction of the Attorney General, that is— (i) constructed of 3.7 ounces of material type 17–4 PH stainless steel in a shape resembling a handgun; and (ii) suitable for testing and calibrating metal detectors. ; (3) in paragraph (3)— (A) in the first sentence, by inserting after of a firearm the following: , including a prototype, ; and (B) by striking the second sentence; and (4) in paragraph (5), by striking shall not apply to any firearm which and all that follows and inserting the following: “shall not apply to— (A) any firearm received by, in the possession of, or under the control of the United States; or (B) the manufacture, importation, possession, transfer, receipt, shipment, or delivery of a firearm by a licensed manufacturer or licensed importer pursuant to an existing contract with the United States. .