New Jersey Statutes Title 2C. The New Jersey Code of Criminal Justice 2C § 39-22

a. A person who lawfully owned a center-fire rifle that is capable of firing a .50 BMG cartridge prohibited under the provisions of paragraph (5) of subsection c. of N.J.S.2C:39-1 on the effective date of P.L.2022, c. 54 (C.2C:39-21 et al.)  1 and does not register it pursuant to section 2 of P.L.2022, c. 54 (C.2C:39-21) may retain possession of that firearm for a period not to exceed one year from that effective date. During that time period, the owner of the prohibited firearm shall either:

b. If the owner of the prohibited firearm elects to render the weapon inoperable, the owner shall file a certification on a form prescribed by the superintendent indicating the date on which the weapon was rendered inoperable. This certification shall be filed with either the chief law enforcement officer of the municipality in which the owner resides or, in the case of an owner who resides in a municipality which does not have a full-time police department, with the superintendent.

c. As used in this section, “inoperable” means that the firearm is altered in such a manner that it cannot be immediately fired and that the owner or possessor of the firearm does not possess or have control over the parts necessary to make the firearm operable.

d. The provisions of this paragraph shall not apply to any antique firearm, curio or relic, or weapon solely used to fire blank ammunition for purpose of a living historical reenactment in accordance with the provisions of paragraph (5) of subsection c. of N.J.S.2C:39-1.