Recently, a letter written to Oklahoma Rep. David Hardin from Glock has circulated around the internet. The letter, dated August 19, urges Oklahoma to pass state legislation that would make it illegal to possess machine gun conversion devices (MCD). Pundits and commentators were quick to react to the leaking of the letter, questioning Glock’s integrity and whether the company is willing to support gun control. The answer, however, is more complicated, and Glock’s motivations arise specifically from events here in New Jersey.
What are MCDs?
The cries for regulation on MCDs have grown out of public demand to address the proliferation of Glock switches, a relatively cheap device that replaces the back plate on a Glock slide, converting them to fully automatic fire. The frequency with which they are used in predominantly inner-city gang violence in major urban centers across the U.S. has increased significantly.
So how does federal law treat MCDs? Section 5845(b) of the NFA defines “machine gun” as:
any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. The term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machine gun, and any combination of parts from which a machine gun can be assembled if such parts are in the possession or under the control of a person (emphasis added).
Federal law, therefore, uses a unified, single definition for complete machine guns, machine gun receivers, and machine gun conversion devices.
Under federal law, an individual is required to apply for and obtain a $200 tax stamp under the NFA in order to possess a machine gun and, under the Hughes Amendment to the Gun Control Act, may only possess machine guns manufactured before 1986 (18 U.S.C. § 922(o)). The Glock Switch was invented in 1996; therefore, no Glock switch would ever be transferable under federal law to individual possessors, as long as the Hughes Amendment remains on the books.
As such, they are illegal in all 50 states and cannot be made legal by state law. The challenge is that, if a local police department arrests someone for committing a crime and that person is found to be in possession of a Glock switch, the case would have to be referred to the DoJ, and that person would have to be prosecuted in federal court in a separate proceeding to any related state court case.
Many states make the possession of a machine gun without proper licensing a felony under state law. This allows states to prosecute these cases without having to refer them to their federal counterparts. The way that states define and regulate machine guns is, in many cases, inconsistent, in some cases using a more narrow definition than federal law, limiting it to just complete, functioning firearms.
As of 2025, almost half of the states have made amendments to their laws to, in some way, address MCDs. While there is variation from state to state, these amendments come in two categories:
- amending the definition of machine gun to mirror federal definitions, or
- creating a new state law category for MCDs, and leaving it up to the states to make determinations as to what meets the definition of an MCD.
In 2023, Indiana passed HEA 1365. That bill amended the state’s definition of a machine gun to exactly mirror the federal definition and then expressly excludes any item from the definition if that item is not required to be registered under the NFA. This leaves Indiana residents in the same position under either federal or state law.
In March of this year, New Jersey introduced A4974, which creates a separate category for MCDs and makes possession of those devices a third-degree crime. That is problematic for several reasons. It takes trafficking in illegal machine guns down to a lesser charge that is PTI-eligible and expungeable; it requires NJ law enforcement agencies to make determinations as to what meets the definition of an MCD; and, as a new separate category, future challenges to constitutional restrictions on machine guns would not necessarily directly apply to New Jersey’s MCD regulations.
Why is Glock Concerned With This Issue?
Glock has found itself at the center of a flurry of lawsuits initiated by anti-gun rights states that have, in complete contradiction to both common sense and the federal Protection of Lawful Commerce in Arms Act (PLCAA), attempted to make Glock liable for unlawful modifications of their firearms by third parties, most of whom acquired those pistols illegally.
New Jersey is leading that charge, with Attorney General Matthew Platkin attempting to invent a new term out of thin air: “switchable firearms.” That term exists nowhere in any state law or federal law. These nuisance lawsuits are a threat to Glock’s very existence. New Jersey’s version of MCD regulation could well lead to our rogue Attorney General attempting to categorize Glock pistols themselves as MCDs.
Taken directly from Glock’s letter to Rep. Hardin:
State criminal MCD laws that mirror federal statutes would better equip law enforcement authorities to remove MCDs from their communities. It would also empower state and local prosecutors to charge and prosecute, holding offenders accountable without having to rely on the United States Attorney’s Office. (emphasis added)
Why Should You Be Concerned About This Issue?
Gun owners have no interest in the illegal trafficking of Glock switches. Most Glock switches in circulation are coming from China, and those shipped through normal channels are simply being missed in the customs process at U.S. ports. Much like the fentanyl crisis, our border control resources can only block so much of it from entering through these channels.
It’s a perfect storm: New Jersey simultaneously treats this issue too lightly, while creating just enough ambiguity that the AG here can continue to target manufacturers like Glock, while also reaching its own determinations as to what a machine gun conversion device is. This leaves the door wide open for the state to define, for example, forced reset triggers as MCDs. In addition, there is room for prosecutorial errors. A drop-in match trigger for an AR-15 could be mistaken for an MCD under this system.
Are Machine Guns Protected Under the Second Amendment?
Based on the current state of Second Amendment jurisprudence, there is a good reason to think that they are. The reality is, however, that the time is not right for this. The current Supreme Court is fairly clearly indicating that the votes are not there. If gun rights advocates want to preserve any chance for a favorable ruling on this issue, the best course of action is to avoid any premature challenge on this question from moving forward, at least until more central questions are resolved, like bans on commonly owned semi-automatic weapons or standard capacity magazines.
With federal courts of appeal still thumbing their noses at what should be clear under Heller and Bruen, and challenges to NFA-regulated items like suppressors and SBRs that fall squarely within the framework of existing law, those cases need to develop before the question of machine guns can proceed. And while there was a lot of movement behind NFA reforms in Congress this spring, there was clearly no legislative appetite for changing the regulations on machine guns and destructive devices.
Having said that, any hope in the future for challenges to restrictions on machine guns is made more complicated if states start creating separate categories of items related to machine guns. A unified framework between state and federal law will make any future possibility of challenging these restrictions more straightforward.
Conclusion
The movement towards state regulation of MCDs is going to continue. Both Glock and individual gun owners benefit from state laws that perfectly mirror federal laws, and there is risk for both gun owners and companies like Glock if states pass laws that create material differences in those definitions. Thus, Glock’s letter is not a betrayal of gun owners, but a reluctant statement that their corporate policy is to comply with the law as is, even if they privately believe it is an infringement on the Second Amendment.
