Boston Municipal Ordinance:
Assault Weapons Registration

The City of Boston has enacted municipal ordinances that impose additional requirements on firearms owners beyond those established by state law. Among these is a ban on the sale and possession of assault weapons and large-capacity magazines, which at the state level are addressed under MGL Chapter 140, Sections 128 and 131M^[1].

Boston's 1989 Assault Weapons OrdinanceBoston does not operate a separate registration of lawfully held pre-ban assault-style firearms. Under Chapter 596 of the Acts of 1989 ("An Act relative to assault weapons in the city of Boston," approved December 9, 1989)^[2], the city makes it unlawful to sell, rent, lease, possess, purchase, barter, display, or transfer an assault weapon or large-capacity magazine, enforced through a seven-member assault-weapon roster board chaired by the police commissioner. The roster board maintains a list of prohibited weapon types. It is not a registry of owners.

Under the post-Chapter 135 framework, state-level registration is handled through the Section 121B electronic system (MIRCS Unified Gun Portal), not the FA-10 system. The FA-10 system handles transfer reporting. Boston imposes no separate firearm registration beyond these state systems. Its 1989 assault-weapons ordinance is a possession-and-sale ban, not a registry.

Impact of Chapter 135

Chapter 135 of the Acts of 2024 restructured the state-level assault weapons ban so that Section 131M contains both the prohibition (subsection a) and the grandfathering framework (subsections b and c). Section 128 was restructured to address dealer licensing violations. Boston's municipal ordinance applies to firearms grandfathered under the state framework. The broader state-level definition of "assault-style firearm" introduced by Chapter 135 may affect which firearms fall under the city's ban.

Other Boston-Specific Regulations

• Enhanced safe storage requirements exceeding state minimums
• Reporting of lost or stolen firearms, which Massachusetts state law (MGL c.140 §121B(c)) requires within 7 days statewide, not a Boston-specific 24-hour rule
Additional restrictions on the discharge of firearms within city limits

Enforcement

Violations of Boston municipal firearms ordinances are subject to fines and may be considered by the licensing authority when evaluating suitability for license renewal.