The proposed bill amends New Jersey's criminal code to establish stricter penalties for the sale and possession of machine gun conversion devices. It introduces new definitions for "machine gun" and "machine gun conversion device," expanding the scope of what is considered illegal. The definition of a machine gun now includes not only the firearm itself but also its frame or receiver, parts designed for conversion, and any combination of parts that can be assembled into a machine gun. The bill categorizes the possession of machine gun conversion devices as a third-degree crime, while the possession of an actual machine gun is classified as a second-degree crime, carrying penalties of five to ten years of imprisonment and fines up to $150,000.

Additionally, the bill modifies existing laws regarding firearms and ammunition, specifically addressing the possession of hollow nose or dum-dum bullets, armor-piercing ammunition, bump stocks, and trigger cranks. It establishes that individuals, except for law enforcement officers or licensed collectors, who knowingly possess these items are guilty of a fourth-degree crime. The bill also prohibits the use of three-dimensional printers for manufacturing firearms or components without proper licensing, imposing severe penalties for violations. Overall, the legislation aims to enhance public safety by tightening regulations on firearms and their components, thereby addressing the potential dangers associated with machine guns and conversion devices.