Weapons: firearms; requirement for all firearm components to contain serial numbers; provide for. Amends 1927 PA 372 (MCL 28.421 - 28.435) by adding sec. 14c.

HB 4479 proposes new regulations for firearms in Michigan, primarily by requiring valid serial numbers on all firearms and certain components. The bill prohibits the manufacture, sale, transfer, or, after an 18-month grace period, the possession of firearms lacking a serial number, as well as "ghost gun precursors" (parts that can be assembled into unserialized firearms). It also outlines conditions under which a license is required to manufacture firearms, such as manufacturing for profit or using 3D printers. This legislation directly affects individuals and entities involved in the manufacturing, assembling, selling, transferring, importing, or possessing of firearms in the state.