The proposed bill in New Jersey establishes criminal penalties for the sale and possession of machine gun conversion devices, amending the definition of "machine gun" to include firearms equipped with such devices. It introduces a new definition for "machine gun conversion device," which refers to any part designed to modify a semiautomatic firearm to enable it to fire multiple rounds with a single trigger pull. The bill also amends existing laws to classify the possession of these devices as a third-degree crime, with penalties running consecutively to those for possessing an assault firearm or machine gun.

Additionally, the bill criminalizes the manufacturing, transporting, shipping, selling, or disposing of machine gun conversion devices, categorizing these actions as third-degree crimes with penalties of three to five years imprisonment and fines up to $15,000. It aims to enhance public safety by tightening regulations on firearms and related devices, including provisions for licensed collectors and law enforcement regarding the possession of certain weapons and ammunition. The act is set to take effect immediately upon passage.