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Prohibited Items & Parts

Last updated January 5, 2026

Learn what Massachusetts law says about prohibited weapons, items and parts.

Undetectable & covert firearms

Massachusetts law prohibits the possession, ownership, sale, transfer, manufacture or assembly, repair, or import of firearms that are designed to evade detection or disguise their true nature. These are referred to as covert firearms and undetectable firearms, both of which are defined in M.G.L. c. 140 § 121 and regulated under § 131N.

A covert firearm is any firearm placed in a camouflaging container, or any firearm (other than a stun gun) that is capable of discharging a bullet or shot and is constructed in a shape that does not resemble a firearm or is not immediately recognizable as one. This includes, but is not limited to:

  • Zip guns
  • Concealed bolt guns
  • Folding guns
  • Firearms disguised as everyday objects such as:
    • Key-chains
    • Pens
    • Canes
    • Wallets
    • Flashlights
    • Cigarette lighters or cigarette packages
  • Flare guns
  • Pellet gun and BB gun conversion kits

An undetectable firearm is defined in two ways:

  • A firearm that, after removal of grips, stocks, and magazines, is not detectable by walk-through metal detectors that are calibrated and operated to detect the federal security exemplar defined in 18 U.S.C. § 922(p)(2)(C); or
  • A major component of a firearm, as defined in 18 U.S.C. § 922(p)(2)(B) that, when inspected by detection devices commonly used at secure public buildings and transit stations, does not generate an image that accurately depicts the shape of the component.

Prohibited parts & modifications

Massachusetts law bans certain firearms parts and modifications. They include, but are not limited to, the following:

Suppressors

Massachusetts law makes it illegal to sell, give, use, or possess suppressors, sometimes referred to as "silencers", except for law enforcement or federally licensed firearms manufacturers (FFL 07).

Citations

Prohibited non-firearm weapons

Massachusetts prohibits certain non-firearm weapons from being carried, manufactured or sold. They include, but are not limited to, the following:

  • Various types of knives and blades
  • Slung shot
  • Brass knuckles, or similar
  • Blowguns
  • Blackjacks
  • Nunchaku, or similar
  • Shurikens, or similar
  • Manrikigusari, or similar

Switchblades

The Supreme Judicial Court of Massachusetts determined in Commonwealth v. Canjura in August, 2024 that switchblades are considered "arms" and protected by the Second Amendment. The ban on switchblades cited in M.G.L. c. 269 § 10(b) was therefore deemed unconstitutional and no longer enforceable. This only applies to switchblades, and the ban on the other items mentioned in that section are technically still in effect.

Citations

Commonwealth v. Canjura

FAQ

Massachusetts law does not prohibit or restrict these accessories. Please note, though, that there are other parts that are restricted as a combination, depending on the firearm platform, which you can read about in the "Assualt-style firearms" section of the "Restricted Firearms" page.

Is body armor legal?

There is no law that prohibits the possession, use or purchase of body armor, or bullet resistant vests, sometimes referred to as "bullet-proof vests". There is a law, however, that makes wearing body armor a separate criminal charge if done during the commission of a felony.

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