SB 331 Michigan Senate · 2025-2026 Regular Session

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 requires all firearm components, including parts used to build unserialized "ghost guns," to have valid serial numbers. It bans selling or possessing unserialized firearms or gun parts after 18 months and mandates licensing for individuals making more than five firearms annually. This affects gun manufacturers, sellers, and owners of unserialized weapons, but exempts law enforcement, antique firearms, licensed dealers, and lawfully manufactured items. The law aims to improve firearm tracking through standardized serial numbering while maintaining existing legal exemptions.
Bill status passed 3 of 5 stages cleared
Introduction
May 2025
Committee Review
Jun 2025
Senate Passage
Jun 2025
House Passage
Governor
Introduced May 29, 2025 Last action Jun 25, 2025
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What changed between versions

Senate Introduced Bill As Passed by the Senate · 8 edits · Jun 25, 2025
MODERATE
This bill adds new Section 14c to Michigan's firearm licensing law, imposing stricter regulations on unserialized firearms, ghost gun precursors, and undetectable weapons. The changes expand criminal penalties for violations and establish new licensing requirements for firearm manufacturing.
Scope change
The bill expands the scope of prohibited conduct to include manufacturing, importing, selling, and possessing unserialized firearms and ghost gun precursors, with specific exemptions for law enforcement, licensed gunsmiths, and certain government entities.
REQUIREMENT

Prohibits knowingly manufacturing, importing, selling, or transferring firearms without valid serial numbers, with an 18-month grace period before possession becomes prohibited.

Bans knowingly importing, purchasing, selling, or transferring ghost gun precursors (frames or receivers without serial numbers).

Prohibits knowingly manufacturing, importing, selling, transferring, or possessing undetectable firearms (made entirely of nonmetal substances that evade security detection).

Requires individuals without manufacturing licenses to have firearms imprinted with serial numbers within 10 days of assembly and notify the state police director.

Prohibits knowingly allowing prohibited persons to manufacture firearms and bans manufacturing firearms without serial numbers for persons prohibited from firearm possession.

ENFORCEMENT

Establishes misdemeanor penalties for first offenses (up to 1 year imprisonment or $5,000 fine) and felony penalties for subsequent offenses (up to 5 years imprisonment or $10,000 fine).

DEFINITION

Creates new definitions for 'ghost gun precursor,' 'undetectable firearm,' 'major component,' and 'unfinished frame or receiver' to clarify what items are regulated.

ELIGIBILITY

Expands exemptions to include forensic laboratories, common carriers transporting firearms, and individuals moving into Michigan who comply with serialization within 90 days.

Floor votes

How they voted

This bill passed the Senate by voice vote (no roll call recorded).
Full legislative history

Actions timeline

Total actions
10
Key actions
3
Committee
5
Jun 25, 2025
Committee
referred to Committee on Government Operations
lower
Jun 25, 2025
Introduced
received on 06/25/2025
lower
Jun 25, 2025
Upper · Passed
PASSED ROLL CALL # 175 YEAS 19 NAYS 17 EXCUSED 1 NOT VOTING 0
upper
Jun 11, 2025
Upper · Passed
REPORTED BY COMMITTEE OF THE WHOLE FAVORABLY WITHOUT AMENDMENT(S)
upper
Jun 10, 2025
Committee
REFERRED TO COMMITTEE OF THE WHOLE
upper
Jun 10, 2025
Upper · Passed
REPORTED FAVORABLY WITHOUT AMENDMENT 6/5/2025
upper
May 29, 2025
Committee
REFERRED TO COMMITTEE ON CIVIL RIGHTS, JUDICIARY, AND PUBLIC SAFETY
upper
May 29, 2025
Introduced
INTRODUCED BY SENATOR MALLORY MCMORROW
upper
1 primary · 8 co-sponsors

Sponsors