Chapter 135 of the Acts of 2024 made significant changes affecting the possession, purchase, transfer, and use of semiautomatic firearms in Massachusetts.
Semiautomatic, large-capacity, and assault-style firearm are different legal classifications.
A semiautomatic firearm may also fall within one or more additional Massachusetts firearm classifications.
What Rules Apply to My Semiautomatic Firearm?
Massachusetts Semiautomatic Firearm Navigator
Answer the following questions for a starting-point explanation.
1. What Does "Semiautomatic" Mean?
Massachusetts defines "semiautomatic" in M.G.L. c. 140, §121.
- extract the fired cartridge case; and
- chamber the next round.
2. Semiautomatic Does Not Automatically Mean Assault-Style
Massachusetts uses separate definitions for:
Describes how the firearm cycles and fires.
A secondary classification based on feeding-device capacity and other statutory criteria.
A separate classification based on feature tests, enumerated firearm families, copies or duplicates, and the statutory roster.
3. FID Cards and Semiautomatic Rifles & Shotguns
M.G.L. c. 140, §129B(c) provides that an FID Card generally authorizes a holder to purchase, transfer, possess, and carry rifles and shotguns that are:
- not large-capacity; and
- not semiautomatic.
The statute expressly states that an FID does not generally authorize the holder to transfer, possess, or carry:
- a semiautomatic rifle;
- a semiautomatic shotgun;
- a large-capacity firearm; or
- other firearms outside the FID's statutory authority.
- an incorporated shooting club; or
- a licensed shooting range.
4. Existing FID Cards — Chapter 135 Transition Provision
Section 153 of Chapter 135 contains an important transitional provision for firearm licenses and cards that were already valid when the law changed.
GOAL cautions that Section 153 speaks specifically about possession and does not clearly grant new authority to purchase, transfer, or carry such a firearm.
Whether this transition provision still applies to a particular person depends on the date the FID was issued or last renewed.
5. LTC Holders
M.G.L. c. 140, §131 provides broader firearm authority to LTC holders.
An LTC generally authorizes a holder to purchase, rent, lease, borrow, possess, and carry firearms, including large-capacity firearms, subject to Massachusetts restrictions.
An LTC holder must still determine whether a semiautomatic firearm is:
- an assault-style firearm;
- a large-capacity firearm;
- properly registered;
- properly serialized;
- lawful to transfer or acquire; and
- subject to another Massachusetts restriction.
6. Residents Ages 18–20
Massachusetts generally limits an LTC application to persons age 21 or older.
Persons ages 18–20 therefore face additional restrictions involving handguns and semiautomatic firearms because an FID does not generally authorize possession of semiautomatic rifles or shotguns.
7. Semiautomatic Handguns
Semiautomatic handguns are not governed by the FID authority in §129B.
A Massachusetts resident generally needs the licensing authority provided by an LTC to possess or carry a handgun unless a specific statutory exemption applies.
A semiautomatic handgun may also require separate review under:
- the assault-style firearm definition;
- large-capacity firearm provisions;
- handgun sales rosters;
- magazine restrictions;
- registration; and
- serialization.
8. Large-Capacity Semiautomatic Firearms
Massachusetts defines "large-capacity firearm" as a secondary designation.
Under M.G.L. c. 140, §121, the designation can include a firearm that is:
- semiautomatic with a fixed large-capacity feeding device;
- semiautomatic and capable of accepting, or readily modifiable to accept, a detachable large-capacity feeding device when the firearm and device are in the same person's possession or under their control in a vehicle;
- equipped with a qualifying high-capacity rotating cylinder; or
- classified as an assault-style firearm.
9. Large-Capacity Feeding Devices
Magazine or feeding-device legality must be analyzed separately from firearm legality.
M.G.L. c. 140, §121 generally defines a large-capacity feeding device as one capable of accepting:
- more than 10 rounds of ammunition; or
- more than 5 shotgun shells,
subject to statutory exclusions.
10. Assault-Style Semiautomatic Rifles
A semiautomatic centerfire rifle capable of accepting a detachable feeding device can meet the assault-style firearm definition if it has at least two of the listed statutory features.
Those features include:
- folding or telescopic stock;
- thumbhole stock or pistol grip;
- forward or second handgrip;
- qualifying threaded barrel; and
- qualifying barrel shroud.
11. Assault-Style Semiautomatic Pistols
A semiautomatic pistol capable of accepting a detachable feeding device can meet the Massachusetts assault-style firearm definition when it has at least two of the specified statutory features.
These can include:
- a feeding device attaching outside the pistol grip;
- a second or forward handgrip;
- a qualifying threaded barrel; and
- a qualifying barrel shroud.
12. Assault-Style Semiautomatic Shotguns
A semiautomatic shotgun can meet the assault-style firearm definition when it includes at least two qualifying features, including certain:
- folding or telescopic stocks;
- thumbhole stocks or pistol grips;
- forward grips; and
- detachable feeding-device capability.
13. Nonresidents
M.G.L. c. 140, §129C(i) and (j) provide limited possession exemptions for qualifying nonresidents who are at least 18.
Those particular exemptions are expressly written for rifles and shotguns that are:
- not large-capacity; and
- not semiautomatic.
The listed purposes include certain:
- hunting;
- shooting-range activity;
- travel in or through Massachusetts; and
- firearm shows or displays.
14. Hunting With Semiautomatic Firearms
Firearm possession law and hunting law operate separately.
Before hunting with a semiautomatic firearm, determine:
- whether you may lawfully possess the firearm;
- whether your license or exemption covers it;
- whether it is large-capacity;
- whether it is assault-style;
- whether the firearm is registered and serialized when required; and
- whether the firearm is a lawful hunting implement for the species and season.
15. Shooting Ranges
The FID provisions contain an important range-use exception.
An FID holder may use certain rifles or shotguns that the FID does not otherwise authorize when:
- the activity occurs at an incorporated shooting club or licensed shooting range; and
- the FID holder is under the direct supervision of an LTC holder.
16. Purchasing Semiautomatic Firearms
Massachusetts purchase authority depends on the purchaser's credential and firearm classification.
M.G.L. c. 140, §128A states that an FID holder over age 18 may purchase or transfer rifles and shotguns that are neither large-capacity nor semiautomatic.
An LTC holder must still determine whether the firearm itself may lawfully be sold or transferred in Massachusetts.
17. Registration
A semiautomatic firearm is subject to the same registration analysis as other firearms under M.G.L. c. 140, §121B.
Registration does not determine whether the firearm is otherwise lawful to possess.
18. Serialization
Semiautomatic firearms must separately comply with serialization requirements under M.G.L. c. 140, §121C when those requirements apply.
Serialization and registration are separate legal requirements.
19. Transportation
Before transporting a semiautomatic firearm, review:
- your license or exemption;
- whether the firearm is large-capacity;
- whether it is an assault-style firearm;
- whether it is loaded;
- vehicle requirements under §131C;
- storage requirements under §131L; and
- feeding-device restrictions under §131M.
20. Rapid-Fire Devices and Automatic Conversion
Massachusetts separately regulates devices or modifications that alter or substantially increase the rate of fire of a semiautomatic firearm.
M.G.L. c. 140, §121 contains definitions for:
- automatic conversion;
- automatic parts;
- rapid-fire trigger activators; and
- trigger modifiers.
21. GOAL Analysis
GOAL identifies semiautomatic firearms as one of the areas most significantly affected by Chapter 135.
GOAL's current concerns include:
- FID-holder possession restrictions;
- the Chapter 135 Section 153 transition provision;
- youth shooters and hunters;
- adults ages 18–20;
- nonresident firearm owners;
- hunting exemptions;
- range-use exemptions;
- large-capacity classification;
- assault-style firearm classification; and
- conflicting or unclear state interpretations.
Semiautomatic Firearm Checklist
LTC, FID, Nonresident LTC, or statutory exemption.
Rifle, shotgun, or handgun.
Review the firearm and feeding device together.
Feature test, enumerated list, copies/duplicates, and roster.
FID and LTC authority differs substantially by age.
Review §121B and 501 CMR 19.
Review §121C and 501 CMR 20.
Review §§131C, 131L, and 131M where applicable.
Home possession, range use, hunting, transfer, purchase, and transportation can trigger different rules.
Semiautomatic firearm law remains an area of active interpretation and litigation.
Primary Sources
- M.G.L. c. 140, §121 — definitions of semiautomatic, large-capacity firearm, assault-style firearm, feeding device, and related terms.
- M.G.L. c. 140, §129B — FID Card authority and restrictions.
- M.G.L. c. 140, §129C — exemptions, including certain nonresident provisions.
- M.G.L. c. 140, §131 — License to Carry.
- M.G.L. c. 140, §131M — assault-style firearms and large-capacity feeding devices.
- M.G.L. c. 140, §128A — firearm purchase and transfer authority.
- Chapter 135 of the Acts of 2024 — including Section 153 transition provision.
- GOAL — Semiautomatic Firearms
- GOAL — FID Cards vs. Semiautomatics
- GOAL — Assault-Style Firearms
- GOAL — Massachusetts Firearm & Hunting Law Resource Center
Massachusetts semiautomatic firearm laws interact with licensing, large-capacity firearm rules, assault-style firearm restrictions, registration, serialization, transportation, hunting, and nonresident laws.
Check current statutes, Commonwealth guidance, and GOAL analysis before purchasing, possessing, transporting, modifying, transferring, or using a semiautomatic firearm.