(a) A person commits an offense who intentionally or knowingly possesses, manufactures, transports, repairs or sells:
(1) An explosive or an explosive weapon;
(2) A device principally designed, made or adapted for delivering or shooting an explosive weapon;
(3) A machine gun;
(4) A short-barrel rifle or shotgun;
(5) Hoax device;
(6) Knuckles; or
(7) Any other implement for infliction of serious bodily injury or death that has no common lawful purpose.

(b) It is a defense to prosecution under this section that the person's conduct:
(1) Was incident to the performance of official duty and pursuant to military regulations in the army, navy, air force, coast guard or marine service of the United States or the Tennessee national guard, or was incident to the performance of official duty in a governmental law enforcement agency or a penal institution;
(2) Was incident to engaging in a lawful commercial or business transaction with an organization identified in subdivision (b)(1);
(3) Was incident to using an explosive or an explosive weapon in a manner reasonably related to a lawful industrial or commercial enterprise;
(4) Was incident to using the weapon in a manner reasonably related to a lawful dramatic performance or scientific research;
(5) Was incident to displaying the weapon in a public museum or exhibition; or
(6) Was licensed by the state of Tennessee as a manufacturer, importer or dealer in weapons; provided, that the manufacture, import, purchase, possession, sale or disposition of weapons is authorized and incident to carrying on the business for which licensed and is for scientific or research purposes or sale or disposition to an organization designated in subdivision (b)(1).

(c) It is an affirmative defense to prosecution under this section that the person must prove by a preponderance of the evidence that:
(1) The person's conduct was relative to dealing with the weapon solely as a curio, ornament or keepsake, and if the weapon is a type described in subdivisions (a)(1)-(4), that it was in a nonfunctioning condition and could not readily be made operable; or
(2) The possession was brief and occurred as a consequence of having found the weapon or taken it from an aggressor.

(d) It is an exception to the application of subsection (a) that the person acquiring or possessing a weapon described in subdivisions (a)(3) or (a)(4) is in full compliance with the requirements of the National Firearms Act (26 U.S.C. §§? 5841-5862).

(e) Subsection (a) shall not apply to the possession, manufacture, transportation, repair, or sale of an explosive if:
(1) The person in question is eighteen (18) years of age or older; and
(2) The possession, manufacture, transport, repair, or sale was incident to creating or using an exploding target for lawful sporting activity, as solely intended by the commercial manufacturer.

(f) (1) An offense under subdivision (a)(1) is a Class B felony.
(2) An offense under subdivisions (a)(2)-(4) is a Class E felony.
(3) An offense under subdivision (a)(5) is a Class C felony.
(4) An offense under subdivisions (a)(6)-(7) is a Class A misdemeanor.