Yes, gun switches are illegal. Federal law classifies them as machineguns, and possessing one is a felony carrying up to 10 years in federal prison and fines as high as $250,000. More than two dozen states add their own criminal penalties on top of the federal ban, so a single device can produce two separate felony prosecutions.
Why Federal Law Treats a Switch as a Machinegun
The National Firearms Act defines “machinegun” broadly enough to cover not just finished automatic weapons but any part designed solely to convert a firearm into one.1Office of the Law Revision Counsel. 26 U.S. Code 5845 – Definitions A gun switch, sometimes called a Glock switch or auto sear, fits squarely inside that definition. The Department of Justice has confirmed that conversion devices are machineguns under the Act whether or not they are installed on a firearm.2Department of Justice. Machinegun Conversion Devices Fact Sheet
That distinction matters. You do not need to own a gun to catch a federal machinegun charge. The switch sitting loose in a drawer is the crime. Federal law prohibits the transfer or possession of machineguns made after May 19, 1986, with narrow exceptions for government agencies and certain federally licensed dealers.3Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Commercially manufactured switches all postdate that cutoff, so no civilian exception applies.
Loose Parts Also Count
The machinegun definition reaches “any combination of parts from which a machinegun can be assembled” when those parts are in someone’s possession or control.1Office of the Law Revision Counsel. 26 U.S. Code 5845 – Definitions If the components sit unassembled on a workbench, prosecutors do not need to prove you put them together. Having the parts and the ability to assemble them is enough.
3D-Printed Switches
The DOJ has expressly acknowledged that people manufacture conversion devices through 3D printing, and it makes no legal difference.2Department of Justice. Machinegun Conversion Devices Fact Sheet A plastic switch printed at home is legally identical to a metal one shipped from overseas. The moment the object exists, it is a machinegun.
Federal Penalties
The consequences scale sharply with the circumstances, and even the baseline is a felony.
Simple Possession
Possessing an unregistered machinegun carries up to 10 years in federal prison.4Office of the Law Revision Counsel. 26 U.S. Code 5871 – Penalties The National Firearms Act sets its fine ceiling at $10,000, but the general federal sentencing statute allows fines up to $250,000 for any felony, and that higher amount controls.5Office of the Law Revision Counsel. 18 U.S. Code 3571 – Sentence of Fine This applies even if the switch was never installed on a firearm and you had no intent to use it.
Possession During a Violent Crime or Drug Offense
If you possess a machinegun during a crime of violence or a drug trafficking offense, federal law imposes a 30-year mandatory minimum, served consecutively with the sentence for the underlying crime. A second such offense triggers a mandatory life sentence.6Office of the Law Revision Counsel. 18 U.S. Code 924 – Penalties Probation is unavailable, and the machinegun sentence cannot run concurrently with anything else.
Prior Felony Record
A person with three or more prior convictions for violent felonies or serious drug offenses who is caught with a firearm faces a 15-year mandatory minimum under the Armed Career Criminal Act. Federal sentencing guidelines treat machineguns as particularly dangerous firearms, which pushes the recommended sentence higher for qualifying offenders.7United States Sentencing Commission. Federal Armed Career Criminals Prevalence Patterns and Pathways
Trafficking and Importation
Shipping, transporting, or transferring firearms in a way that affects foreign commerce carries up to 15 years in federal prison under the federal firearms trafficking statute.8Office of the Law Revision Counsel. 18 USC 933 – Trafficking in Firearms Most switches sold online are smuggled into the United States from China, typically concealed in air cargo, and federal authorities have moved aggressively against these supply chains, including one operation that seized more than 3,000 conversion devices and took down roughly 360 selling domains.9Department of Justice. Federal Authorities Seize Two Website Domains Used to Import Illegal Machine Gun Conversion Devices
State Laws Stack on Top
Federal law sets the floor. More than two dozen states have their own statutes banning gun switches or the broader category of automatic conversion devices, and possession is typically a felony carrying multiple years in prison plus fines that vary by jurisdiction.
A state charge does not insulate you from federal prosecution, and federal charges do not preempt the state case. Authorities regularly run parallel prosecutions, so a single switch can produce two separate felony convictions with independent sentences. A felony at either level also strips your right to possess any firearm going forward.
Forced Reset Triggers Are Not the Same Thing
Switches are sometimes confused with forced reset triggers, but the two are legally distinct. A switch converts a firearm to fire automatically on a single trigger pull. A forced reset trigger uses a spring to push the trigger forward faster after each shot, and the shooter still pulls it separately for every round.
The ATF originally classified FRTs as machineguns, but a 2024 federal court ruling determined that specific FRT models do not meet the statutory definition. A follow-on settlement between the DOJ and affected manufacturers confirmed that possessing or transferring eligible FRTs does not violate federal law. That same settlement is explicit that switches, drop-in auto sears, lightning links, and similar conversion devices are not covered and remain illegal.10Bureau of Alcohol, Tobacco, Firearms and Explosives. Rare Breed Triggers FRT-15s and Wide-Open Triggers WOTs Return
If You Already Have One
If you discover a switch in your possession, or someone hands one to you, the ATF asks that you contact your local ATF field office to arrange a safe surrender.11Bureau of Alcohol, Tobacco, Firearms and Explosives. U.S. Attorney and ATF Release New Public Service Announcement Warning Against Possession of Machine Gun Conversion Devices Do not try to destroy the device yourself and assume that closes the matter. The ATF’s destruction standards require that a firearm component be rendered completely non-restorable, and casually breaking or discarding a switch will not necessarily satisfy that standard. The safer route is to let the field office handle it.