NJ S3893

Adds "machine gun conversion device" to New Jersey's definition of prohibited weapons, defined as any device capable of converting a firearm into a machine gun

Expands the definition of "machine gun" to include the frame or receiver of such firearms, parts designed for converting firearms into machine guns, and any combination of parts from which a machine gun can be assembled

Makes possession of a machine gun conversion device (when not in possession of a firearm to which it may be affixed) a third-degree crime, the same penalty as possession of bump stocks or trigger cranks

Makes manufacturing, transporting, shipping, selling, or disposing of a machine gun conversion device a third-degree crime

Clarifies that possession of a bump stock, trigger crank, or machine gun conversion device that is affixed to a firearm would be prosecuted under the more serious machine gun possession statute (second-degree crime) rather than as a standalone device offense