4. a. No licensed manufacturer, wholesale dealer of firearms, or retail dealer of firearms in possession of a bump stock as defined in subsection ee. of N.J.S.2C:39-1 or a trigger crank as defined in subsection ff. of N.J.S.2C:39-1 on the effective date of P.L.2017, c.323 (C.2C:58-14.1 et al.) who voluntarily surrenders the bump stock or trigger crank in accordance with the provisions of N.J.S.2C:39-12 or otherwise lawfully disposes of the bump stock or trigger crank within 30 days of the effective date of P.L.2017, c.323 (C.2C:58-14.1 et al.) shall be convicted of an offense for possession of a bump stock or trigger crank under subsection l. of N.J.S.2C:39-3 or unlawful manufacture, transport, shipment, sale, or disposition of a bump stock or trigger crank under subsection j. of N.J.S.2C:39-9.
b. Except as otherwise provided in subsection a. of this section with respect to licensed manufacturers, wholesale dealers of firearms, and retail dealers of firearms, no person in possession of a bump stock as defined in subsection ee. of N.J.S.2C:39-1 or a trigger crank as defined in subsection ff. of N.J.S.2C:39-1 on the effective date of P.L.2017, c.323 (C.2C:58-14.1 et al.) who voluntarily surrenders the bump stock or trigger crank in accordance with the provisions of N.J.S.2C:39-12 or otherwise lawfully disposes of the bump stock or trigger crank within 90 days of the effective date of P.L.2017, c.323 (C.2C:58-14.1 et al.) shall be convicted of an offense for possession of a bump stock or trigger crank under subsection l. of N.J.S.2C:39-3.