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.
SB 331 would amend Michigan’s firearms code to create a new section regulating so-called “ghost guns,” unfinished frames and receivers, and undetectable firearms. The bill generally prohibits the manufacture, assembly, import, sale, transfer, purchase, or possession of firearms and firearm components that do not bear a valid serial number, with a delayed possession ban taking effect 18 months after enactment for un-serialized firearms and ghost gun precursors. It also bans undetectable firearms and restricts transfers involving firearms made by unlicensed manufacturers unless they are serialized in compliance with federal requirements.
The bill sets out a licensing and serialization framework for people who manufacture firearms in Michigan. A person must have a federal license to manufacture firearms if they make guns for profit, make more than five firearms or frames/receivers in a calendar year for personal use, or use a 3D printer or CNC milling machine to make a firearm or frame/receiver. Unlicensed makers must serialize the firearm or frame/receiver within 10 days, notify the state police director, and provide identifying information. The bill also defines key terms such as “ghost gun precursor,” “unfinished frame or receiver,” “undetectable firearm,” and “valid serial number,” and it includes exceptions for antiques, law enforcement, military, carriers, buyback programs, gunsmiths/manufacturers/importers, and certain temporary possession or transport situations.
If enacted, SB 331 would add new criminal penalties to Michigan law for violations of the serialization and ghost-gun restrictions. A first offense would be a misdemeanor punishable by up to one year in jail and/or a $5,000 fine, while repeat offenses would be felonies punishable by up to five years in prison and/or a $10,000 fine. The bill would also expand state enforcement authority over firearm components by requiring serialization by federally authorized entities and by tying compliance to federal firearm-identification standards.
The general sentiment reflected in the bill’s progress is supportive but closely divided. The bill was reported favorably out of committee and then passed the Senate on a narrow roll call vote, indicating meaningful backing but also substantial opposition. The absence of recorded committee testimony limits insight into specific arguments, but the vote margins suggest the measure was viewed by supporters as a public-safety and enforcement tool, while opponents likely objected to its impact on lawful gun owners, hobbyists, and home manufacturing.
The main points of contention are the breadth of the restrictions and how they apply to private gun making. The bill reaches beyond completed firearms to unfinished frames and receivers, and it would require licensing for certain home-built firearms, including those made with 3D printers or CNC machines. Critics are likely to focus on the practical burden of serialization, the 18-month possession ban for existing un-serialized items, and the inclusion of unfinished components as regulated items, while supporters are likely to emphasize closing loopholes for untraceable and undetectable weapons and preventing access by prohibited persons.
SB 331 would amend 1927 PA 372 by adding a new section 14c that creates statewide restrictions on un-serialized firearms, ghost gun precursors, unfinished frames and receivers, and undetectable firearms. It would impose new duties on unlicensed firearm makers to serialize and report newly made firearms or components, require a manufacturing license in specified circumstances, and establish criminal penalties for violations. The bill would affect private gun owners, hobbyists, home builders, sellers, manufacturers, gunsmiths, law enforcement, carriers, and entities authorized to serialize firearms, while preserving several exemptions for antiques, law enforcement, military, buybacks, and lawful transport or transfer for serialization.
The bill appears to have received enough support to advance, but not by a wide margin. It was reported favorably from committee and then passed the Senate by a close 19-17 vote, suggesting a polarized debate. The available record does not include committee testimony, but the vote pattern indicates that supporters and opponents were both active and that the measure was controversial rather than broadly consensus-driven.
The central dispute is over whether the bill is a necessary public-safety measure or an overbroad restriction on lawful firearm ownership and home manufacture. Supporters are likely focused on preventing untraceable “ghost guns,” limiting access by prohibited persons, and addressing undetectable firearms. Opponents are likely concerned about the reach of the law into unfinished frames and receivers, the 3D printing/CNC provisions, the five-gun threshold for personal manufacture, and the requirement that existing un-serialized firearms and components be brought into compliance within the bill’s deadlines.