Are Binary Triggers Legal in Illinois?

Short answer: No, binary triggers are illegal to possess or sell in Illinois. The state's criminal code defines any weapon that shoots more than one shot 'by a single function of the trigger' as a machine gun.

Are Binary Triggers Legal in Illinois?

No, binary triggers are illegal to possess or sell in Illinois. The state's criminal code defines any weapon that shoots more than one shot 'by a single function of the trigger' as a machine gun. Illinois law interprets the pull-and-release action of a binary trigger as a single function.

Understanding Illinois's Definition of a Machine Gun

The core of the binary trigger issue in Illinois comes down to legal definitions. Unlike federal law, which has a more specific definition, Illinois law is broader and more encompassing. The relevant statute, 720 ILCS 5/24-1(a)(7), defines a machine gun as any firearm that is capable of shooting 'more than one shot, without manual reloading, by a single function of the trigger.' This specific phrasing is the reason binary triggers are considered illegal in the state.

The key phrase is 'single function of the trigger.' Proponents of binary triggers argue that pulling the trigger and releasing the trigger are two distinct actions. However, Illinois courts and law enforcement interpret the complete cycle—from the initial pull to the trigger's reset upon release—as one single function. Because this single, complete function results in the discharge of two rounds, the device falls under the state's machine gun definition. This interpretation effectively bans binary triggers, regardless of how the ATF classifies them at the federal level.

This isn't a new development. The state's broad definition has been on the books for years, long before binary triggers became popular accessories. It's a fundamental aspect of Illinois firearm law that residents must understand. The state's position is that any device that increases the cyclical rate of fire through a mechanism tied to a single trigger cycle is prohibited. You can't simply bolt on a part that achieves a machine-gun-like effect and expect it to be legal. The state looks at the result, not just the mechanical minutiae that differentiates it from a traditional machine gun.

How Binary Trigger Mechanics Conflict with State Law

To grasp why Illinois law ensnares these devices, you need to understand how they work. A standard semi-automatic trigger fires one round when you pull the trigger. The mechanism then resets, and the trigger must be fully released and pulled again to fire another round. It's a one-to-one relationship: one pull, one shot. A fully automatic trigger, by contrast, will fire continuously as long as the trigger is held down and ammunition is available.

A binary trigger operates in a middle ground. It features a third selector position that, when engaged, modifies the trigger's function. In this mode, one round is fired when the trigger is pulled to the rear, and a second round is fired when the trigger is released and moves forward to its reset position. This technical distinction is what allows them to be legal under current federal law, which defines a machine gun based on a continuous stream of fire with a single pull. But as we've established, Illinois law is different.

The conflict arises because the entire process is initiated by that one 'function' of pulling the trigger. The release is not considered a separate, independent action in the eyes of Illinois law; it's the conclusion of the first action. This is a critical distinction from the laws in more permissive states. For instance, understanding the legality of binary triggers in Indiana shows just how different interpretations can be across state lines, where the focus might align more closely with federal definitions.

The Protect Illinois Communities Act (PICA)

If the existing machine gun statute wasn't clear enough, the 2023 passage of the Protect Illinois Communities Act (PICA) added another layer of prohibition. PICA, also known as HB 5471, introduced sweeping changes to Illinois gun laws, including a ban on so-called 'assault weapons' and certain accessories. Critically, the act explicitly bans any 'rapid-fire device.'

The law defines a rapid-fire device as 'a part, kit, tool, accessory, or device that is designed to and functions to accelerate the rate of fire of a semi-automatic firearm beyond the standard rate of fire for semi-automatic firearms that is not equipped with that device.' It goes on to state that this includes, but is not limited to, 'a new trigger that fires both when the trigger is pulled and when the trigger is released.' This language directly and unambiguously targets binary triggers, removing any room for creative legal interpretation that might have existed before.

PICA solidifies their illegal status, making it clear that possessing a binary trigger is not a gray area but a direct violation of current Illinois law. This act makes it easier for prosecutors to secure a conviction without having to argue the nuanced interpretation of the older 'single function of thetrigger' clause. The law now has a specific clause that names the mechanism itself as illegal, making compliance with the law straightforward. Anyone considering how to buy a gun in Illinois needs to be acutely aware of these PICA restrictions on parts and accessories.

Federal vs. State Law: A Crucial Distinction

A common source of confusion for gun owners is the difference between federal and state regulations. The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) has, on multiple occasions, issued opinion letters stating that most common binary trigger designs, like those from Franklin Armory or Fostech, do not meet the federal definition of a 'machinegun' under the National Firearms Act (NFA). This is because the NFA's definition is more focused on the 'single pull' resulting in continuous fire.

However, an ATF opinion does not override state law. States are free to enact firearm laws that are stricter than federal ones, and Illinois has done exactly that. The fact that you can legally purchase a binary trigger in many other states or from an online retailer that will ship to those states is irrelevant within Illinois's borders. Possession is the crime. This principle applies to other firearm accessories as well. For example, the ATF's ruling on forced reset triggers is a separate federal matter, and shooters should always check local laws first, as we explain in our article on forced reset trigger legality in Florida.

The bottom line is simple: federal legality is the floor, not the ceiling. Illinois has built a much more restrictive structure on top of that floor. Gun owners in the state must base their compliance on the Illinois Compiled Statutes and PICA, not on ATF letters or what's legal in Texas, Indiana, or Florida. Thinking you can import a part that is popular on rifles like the SIG Sauer MPX in other states is a surefire way to run into legal trouble in Illinois.

Penalties for Possession in Illinois

The legal consequences for possessing a binary trigger in Illinois are severe. Under the state's machine gun statute, unlawful possession is a Class X felony. This is the most serious class of felony in Illinois outside of first-degree murder. A conviction for a Class X felony carries a mandatory minimum prison sentence of 6 to 30 years, with no possibility of probation.

Under PICA, possession of a prohibited 'rapid-fire device' is also a felony, although penalties can vary based on the specific circumstances of the charge. Regardless of which statute is used for prosecution, the individual faces life-altering consequences, including the permanent loss of their Second Amendment rights, substantial fines, and a lengthy prison term. These are not minor infractions; they are among the most serious firearm offenses in the state.

It's also worth noting that these penalties apply to the device itself. Even if the binary trigger is not installed in a firearm, simple possession of the part is a violation. Law enforcement and prosecutors do not need to prove intent to use it; owning the prohibited item is sufficient for a charge. Before adding any aftermarket parts to a firearm, it's essential to understand not just the function but also the potential impact on the firearm's value and legality. Getting an accurate assessment of a firearm's configuration is a key part of understanding its true gun value and ensuring it's compliant with all applicable laws.