27 CFR § 478.99 - Certain prohibited sales or deliveries.
(a) Interstate sales or deliveries. A licensed importer, licensed manufacturer, licensed dealer, or licensed collector shall not sell or deliver any firearm to any person not licensed under this part and who the licensee knows or has reasonable cause to believe does not reside in (or if a corporation or other business entity, does not maintain a place of business in) the State in which the licensee's place of business or activity is located: Provided, That the foregoing provisions of this paragraph (1) shall not apply to the sale or delivery of a rifle or shotgun (curio or relic, in the case of a licensed collector) to a resident of a State other than the State in which the licensee's place of business or collection premises is located if the requirements of § 478.96(c) are fully met, and (2) shall not apply to the loan or rental of a firearm to any person for temporary use for lawful sporting purposes (see § 478.97).
(b) Sales or deliveries to underaged persons. A licensed importer, licensed manufacturer, licensed dealer, or licensed collector shall not sell or deliver (1) any firearm or ammunition to any individual who the importer, manufacturer, dealer, or collector knows or has reasonable cause to believe is less than 18 years of age, and, if the firearm, or ammunition, is other than a shotgun or rifle, or ammunition for a shotgun or rifle, to any individual who the importer, manufacturer, dealer, or collector knows or has reasonable cause to believe is less than 21 years of age, or (2) any firearm to any person in any State where the purchase or possession by such person of such firearm would be in violation of any State law or any published ordinance applicable at the place of sale, delivery, or other disposition, unless the importer, manufacturer, dealer, or collector knows or has reasonable cause to believe that the purchase or possession would not be in violation of such State law or such published ordinance.
(c) Sales or deliveries to prohibited categories of persons. A licensed manufacturer, licensed importer, licensed dealer, or licensed collector shall not sell or otherwise dispose of any firearm or ammunition to any person knowing or having reasonable cause to believe that such person:
(2) Is a fugitive from justice;
(3) Is an unlawful user of or addicted to any controlled substance (as defined in section 102 of the Controlled Substance Act, 21 U.S.C. 802);
(4) Has been adjudicated as a mental defective or has been committed to any mental institution;
(5) Is an alien illegally or unlawfully in the United States or, except as provided in § 478.32(f), is an alien who has been admitted to the United States under a nonimmigrant visa: Provided, That the provisions of this paragraph (c)(5) do not apply to any alien who has been lawfully admitted to the United States under a nonimmigrant visa if that alien is—
(i) Admitted to the United States for lawful hunting or sporting purposes or is in possession of a hunting license or permit lawfully issued in the United States;
(ii) An official representative of a foreign government who is either accredited to the United States Government or the Government's mission to an international organization having its headquarters in the United States or en route to or from another country to which that alien is accredited. This exception only applies if the firearm or ammunition is shipped, transported, possessed, or received in the representative's official capacity;
(iii) An official of a foreign government or a distinguished foreign visitor who has been so designated by the Department of State. This exception only applies if the firearm or ammunition is shipped, transported, possessed, or received in the official's or visitor's official capacity, except if the visitor is a private individual who does not have an official capacity; or
(iv) A foreign law enforcement officer of a friendly foreign government entering the United States on official law enforcement business;
(6) Has been discharged from the Armed Forces under dishonorable conditions;
(7) Who, having been a citizen of the United States, has renounced citizenship;
(8) Is subject to a court order that restrains such person from harassing, stalking, or threatening an intimate partner of such person or child of such intimate partner or person, or engaging in other conduct that would place an intimate partner in reasonable fear of bodily injury to the partner or child, except that this paragraph shall only apply to a court order that—
(A) Includes a finding that such person represents a credible threat to the physical safety of such intimate partner or child; or
(B) By its terms explicitly prohibits the use, attempted use, or threatened use of physical force against such intimate partner or child that would reasonably be expected to cause bodily injury, or
(9) Has been convicted of a misdemeanor crime of domestic violence.
(d) Manufacture, importation, and sale of armor piercing ammunition by licensed importers and licensed manufacturers. A licensed importer or licensed manufacturer shall not import or manufacture armor piercing ammunition or sell or deliver such ammunition, except:
(1) For use of the United States or any department or agency thereof or any State or any department, agency, or political subdivision thereof;
(2) For the purpose of exportation; or
(3) For the purpose of testing or experimentation authorized by the Director under the provisions of § 478.149.
(e) Transfer of armor piercing ammunition by licensed dealers. A licensed dealer shall not willfully transfer armor piercing ammunition: Provided, That armor piercing ammunition received and maintained by the licensed dealer as business inventory prior to August 28, 1986, may be transferred to any department or agency of the United States or any State or political subdivision thereof if a record of such ammunition is maintained in the form and manner prescribed by § 478.125(c). Any licensed dealer who violates this paragraph is subject to license revocation. See subpart E of this part. For purposes of this paragraph, the Director shall furnish each licensed dealer information defining which projectiles are considered armor piercing. Such information may not be all-inclusive for purposes of the prohibition on manufacture, importation, or sale or delivery by a manufacturer or importer of such ammunition or 18 U.S.C. 929 relating to criminal misuse of such ammunition.