18 U.S.C. § 845

(a) Except in the case of subsection ( l ), (m), (n), or ( o ) of section 842 and subsections (d), (e), (f), (g), (h), and (i) of section 844 of this title , this chapter shall not apply to: (1) aspects of the transportation of explosive materials via railroad, water, highway, or air that pertain to safety, including security, and are regulated by the Department of Transportation or the Department of Homeland Security; (2) the use of explosive materials in medicines and medicinal agents in the forms prescribed by the official United States Pharmacopeia, or the National Formulary; (3) the transportation, shipment, receipt, or importation of explosive materials for delivery to any agency of the United States or to any State or political subdivision thereof; (4) small arms ammunition and components thereof; (5) commercially manufactured black powder in quantities not to exceed fifty pounds, percussion caps, safety and pyrotechnic fuses, quills, quick and slow matches, and friction primers, intended to be used solely for sporting, recreational, or cultural purposes in antique firearms as defined in section 921(a)(16) of title 18 of the United States Code, or in antique devices as exempted from the term “destructive device” in section 921(a)(4) of title 18 of the United States Code; (6) the manufacture under the regulation of the military department of the United States of explosive materials for, or their distribution to or storage or possession by the military or naval services or other agencies of the United States; or to arsenals, navy yards, depots, or other establishments owned by, or operated by or on behalf of, the United States 1 1 So in original. Probably should be followed by a semicolon. and (7) the transportation, shipment, receipt, or importation of display fireworks materials for delivery to a federally recognized Indian tribe or tribal agency. (b) (1) A person who is prohibited from shipping, transporting, receiving, or possessing any explosive under section 842(i) may apply to the Attorney General for relief from such prohibition. (2) The Attorney General may grant the relief requested under paragraph (1) if the Attorney General determines that the circumstances regarding the applicability of section 842(i), and the applicant’s record and reputation, are such that the applicant will not be likely to act in a manner dangerous to public safety and that the granting of such relief is not contrary to the public interest. (3) A licensee or permittee who applies for relief, under this subsection, from the disabilities incurred under this chapter as a result of an indictment for or conviction of a crime punishable by imprisonment for a term exceeding 1 year shall not be barred by such disability from further operations under the license or permit pending final action on an application for relief filed pursuant to this section. (c) It is an affirmative defense against any proceeding involving subsections ( l ) through ( o ) of section 842 if the proponent proves by a preponderance of the evidence that the plastic explosive— (1) consisted of a small amount of plastic explosive intended for and utilized solely in lawful— (A) research, development, or testing of new or modified explosive materials; (B) training in explosives detection or development or testing of explosives detection equipment; or (C) forensic science purposes; or (2) was plastic explosive that, within 3 years after the date of enactment of the Antiterrorism and Effective Death Penalty Act of 1996, will be or is incorporated in a military device within the territory of the United States and remains an integral part of such military device, or is intended to be, or is incorporated in, and remains an integral part of a military device that is intended to become, or has become, the property of any agency of the United States performing military or police functions (including any military reserve component) or the National Guard of any State, wherever such device is located. (3) For purposes of this subsection, the term “military device” includes, but is not restricted to, shells, bombs, projectiles, mines, missiles, rockets, shaped charges, grenades, perforators, and similar devices lawfully manufactured exclusively for military or police purposes.