Are Binary Triggers Legal in Massachusetts? State Law…

Are Binary Triggers Legal in Massachusetts?

No, binary triggers are not legal for civilian possession in Massachusetts. They are classified as machine guns under Massachusetts General Law (M.G.L. c. 140, § 121). The state's definition includes any part that converts a weapon to fire more than one shot per single trigger function.

The Core of the Issue: Massachusetts General Law c. 140, § 121

The legal status of binary triggers in Massachusetts hinges entirely on the state's uniquely broad definition of a 'machine gun'. Unlike federal law, which focuses on continuous fire from a single pull, Massachusetts General Law chapter 140, section 121 defines a machine gun as a weapon that shoots 'more than one shot, without manual reloading, by a single function of the trigger'. The law goes on to include 'any part designed and intended for use in converting a weapon into a machine gun'.

This 'single function' language is the critical element. The state's interpretation, clarified in a 2017 advisory from the Executive Office of Public Safety and Security (EOPSS), is that the entire cycle of pulling and releasing the trigger constitutes a single function. Since a binary trigger fires one round on the pull and a second on the release, it discharges two rounds per 'single function' in the eyes of Massachusetts law. This interpretation effectively reclassifies the trigger system as a machine gun, making it illegal for residents who do not possess a specific and rarely issued machine gun license.

This creates a significant legal hazard for gun owners. A device that can be purchased legally under federal guidelines is considered contraband in Massachusetts. This discrepancy underscores the importance of understanding local statutes before making any firearm modifications. The process is far more complex than the standard steps outlined in guides on how to buy a gun, which often don't account for such state-specific nuances.

Mechanical Function vs. Legal Interpretation

To understand the legal conflict, one must first grasp the mechanics. A standard semi-automatic trigger operates on a simple principle: one pull of the trigger fires one round. The trigger must then be released to reset the sear before another round can be fired. A binary trigger modifies this. It fires one round on the pull, just like a standard trigger. However, it also fires a second round upon the release of the trigger.

Proponents argue that these are two separate actions—a pull and a release—each firing a single round, thus not meeting the definition of automatic fire. This is the reasoning the federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has generally accepted, keeping these devices from being classified as machine guns at the federal level. The ATF sees two distinct manipulations of the trigger, even if they happen in quick succession.

Massachusetts, however, rejects this mechanical distinction in favor of a holistic legal interpretation. The state views the complete operation, from initial pull to final release, as one integrated 'function'. Because this single, complete function results in two shots, the device falls under the state's machine gun ban. This strict interpretation also applies to other rapid-fire devices. The legal landscape for items like this is complex and varies wildly, similar to the situation where people ask if forced reset triggers are legal in Florida, where state law also provides the final answer.

Federal vs. State Law: A Critical Distinction

A common point of confusion for firearm owners is the difference between federal and state law. At the federal level, the ATF has issued opinion letters stating that specific binary trigger designs, like the Franklin Armory BFSIII, do not constitute machine guns. The federal definition in the National Firearms Act (NFA) defines a machine gun as a weapon that fires 'automatically more than one shot, without manual reloading, by a single function of the trigger'. The ATF has historically interpreted 'function' as the pull.

This federal stance is completely irrelevant within the Commonwealth of Massachusetts. The U.S. Constitution allows states to enact stricter gun control laws than those set by the federal government. Massachusetts has done exactly that. Therefore, an ATF approval letter for a binary trigger offers no legal protection to a resident of Massachusetts. The state law is the prevailing authority, and it is unambiguous in its classification.

This legal divergence means that a Massachusetts resident cannot legally purchase a binary trigger from another state and bring it home, nor can they possess one obtained prior to the state's clarification. The laws from one state to the next can be night and day; for example, the rules discussed in our guide on binary triggers in Tennessee are far more permissive. Always prioritize your local state and municipal codes over federal guidelines when it comes to firearm accessories.

Penalties and Enforcement in the Bay State

The consequences for possessing a binary trigger in Massachusetts are severe. Because the state classifies the device as a machine gun, possession is prosecuted under M.G.L. chapter 269, section 10, which governs the unlawful possession of firearms. A conviction for possessing an unlicensed machine gun is a felony offense.

The penalties can include significant prison time, potentially up to life in state prison, although sentences often range from a mandatory minimum of several years to over a decade, along with substantial fines. Importantly, the law criminalizes possession of not just an assembled weapon with a binary trigger but also the part itself. The statute's language explicitly covers 'any part designed and intended for use in converting a weapon into a machine gun'. This means that simply owning an uninstalled binary trigger kit is a felony.

Given these harsh penalties, it's not worth the risk. While you can find a wide array of firearm accessories and parts when you browse all gun listings online, Massachusetts residents must exercise extreme caution to ensure any purchase is compliant with the state's restrictive laws. It's also vital to understand the market value of your existing firearms, as knowing your true gun value can be important for legal sales and transfers.

Are There Any Legal Paths to Ownership?

For the vast majority of citizens, there is no legal way to own a binary trigger in Massachusetts. The only theoretical exception would be for an individual who holds a Massachusetts machine gun license. However, these licenses are exceptionally difficult to obtain and are generally restricted to bona fide firearms manufacturers, authorized dealers for law enforcement or military contracts, and in very rare cases, certified collectors.

The application process is stringent, requires a demonstrable 'proper purpose' for possessing a machine gun, and is subject to the discretion of local and state authorities. For the average gun owner, collector, or sport shooter, acquiring such a license is practically impossible. Therefore, the law functions as a complete ban on binary triggers for the general public.

This restrictive environment also impacts how firearms are sold and transferred. Navigating the legal requirements is a complex process, whether you are buying or trying to sell a gun in Massachusetts. All transactions must adhere to strict state protocols, and the presence of any prohibited part can turn a simple sale into a serious criminal matter.