Automatic weapons are not flatly illegal in the United States, but federal law limits civilian ownership to a fixed pool of machineguns that were already registered before May 19, 1986. Buying one legally means clearing an extensive federal background check, paying a $200 transfer tax, and typically spending well into five figures because no new automatic weapons can enter the civilian market. Around a dozen states ban civilian possession entirely, and having an unregistered machinegun anywhere in the country is a federal felony carrying up to ten years in prison.
What Counts as a Machinegun Under Federal Law
Federal law defines a machinegun as any weapon that fires more than one round with a single pull of the trigger, without reloading between shots. The definition reaches further than the gun itself. It also covers the frame or receiver of such a weapon, any part designed solely to convert a firearm into a machinegun, and any collection of parts that could be assembled into one while in a person’s possession.1Office of the Law Revision Counsel. 26 USC 5845 – Definitions
That last piece surprises people. You don’t need a functioning automatic weapon to face federal charges. Possessing internal components meant to convert a semiautomatic rifle can be enough on its own, even if nothing is ever installed.
Why the Civilian Supply Is Frozen
Two federal statutes set the ground rules. The National Firearms Act of 1934 didn’t ban machineguns. Congress instead imposed a $200 tax on every transfer and required each NFA firearm to be registered with the federal government.2Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act In 1934 dollars, that $200 was roughly $4,900 today, a figure meant to price the guns out of reach.
The bigger change came in 1986. The Firearm Owners’ Protection Act, through what’s known as the Hughes Amendment, made it illegal for any civilian to transfer or possess a machinegun not already lawfully registered before May 19, 1986.3Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts That single date closed the door. No manufacturer can produce new automatic weapons for private sale, and no civilian can add one to the registry. Every legally transferable machinegun in the country is at least four decades old, and the pool shrinks a bit each year as firearms are lost, destroyed, or seized.
How a Civilian Legally Buys One
The only automatic weapons available to civilians are those already registered before the 1986 cutoff, commonly called transferable machineguns. The Bureau of Alcohol, Tobacco, Firearms and Explosives runs the transfer process, and it looks nothing like an ordinary gun purchase.
Who Qualifies
A buyer purchasing from a licensed dealer must be at least 21 and cannot be a “prohibited person” under federal law, a category that includes anyone with a felony conviction among other disqualifiers.3Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Most transfers move through a Class 3 Special Occupational Taxpayer, a federally licensed dealer authorized to handle NFA firearms.4Bureau of Alcohol, Tobacco, Firearms and Explosives. Application for Tax-Exempt Transfer of Firearm and Registration to Special Occupational Taxpayer Dealer transfer and storage fees generally run between $50 and $200.
The Paperwork and Tax
The buyer completes ATF Form 4, the “Application for Tax Paid Transfer and Registration of Firearm.”5Bureau of Alcohol, Tobacco, Firearms and Explosives. Application for Tax Paid Transfer and Registration of Firearm – ATF Form 4 (5320.4) The full submission includes the completed Form 4 identifying buyer, seller, and firearm; two FBI fingerprint cards (Form FD-258); a passport-style photograph taken within the last six months; and the $200 transfer tax. The $200 tax still applies to machineguns and destructive devices even after recent legislation dropped the tax to $0 for other NFA items like suppressors and short-barreled rifles.6Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transfer and Register NFA Firearm (Tax-Paid) – ATF Form 5320.4
The Wait
Form 4 approvals once dragged past a year, and the reputation persists. The reality has shifted with ATF’s eForms system. As of February 2026, the average wait for an individual eForms application was 10 days, and paper submissions averaged about 21 days. Trust applications ran 26 days for eForms and 24 days for paper.7Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times Individual cases can take longer if the ATF wants more research. During the wait, the firearm stays with the seller. The buyer takes possession only after the ATF approves the Form 4, affixes a tax stamp, and returns the approved form, which then serves as permanent proof of registration and must be kept with the firearm.6Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transfer and Register NFA Firearm (Tax-Paid) – ATF Form 5320.4
What It Actually Costs
Frozen supply has turned pre-1986 machineguns into collector’s items. Entry-level transferables, typically MAC-10 and MAC-11 variants, sell for roughly $8,000 to $15,000. M16 variants sold on GunBroker.com in February 2026 for between $26,000 and $37,000, with a Colt M16 package listed at $36,999.8GunBroker.com. 7 Most Expensive Machine Guns Sold on GunBroker – February 2026 Rarer models like transferable Thompson submachine guns or H&K MP5s routinely clear $40,000. Add the $200 tax, dealer fees, and any state requirements, and legal machinegun ownership starts well into five figures.
Where You Live Can Override Federal Approval
Federal approval doesn’t override state law. Roughly a dozen states and the District of Columbia ban private machinegun possession outright, regardless of NFA registration. California, New York, Illinois, Hawaii, New Jersey, Massachusetts, and Delaware are among them. In those places, an approved Form 4 and a paid tax stamp still leave a person committing a state crime the moment they take possession.
Other states generally allow ownership for anyone with proper federal registration, though some layer on additional licensing or restrictions. Anyone considering a purchase should confirm the law in their state and municipality before spending money on a transfer they can’t lawfully complete at home.
Penalties for Unlawful Possession
Federal law gives prosecutors two overlapping routes, and they can charge under either or both.
The National Firearms Act makes it a crime to possess an unregistered machinegun or to receive one transferred in violation of the NFA.9Office of the Law Revision Counsel. 26 USC 5861 – Prohibited Acts10Office of the Law Revision Counsel. 26 USC 5871 – Penalties11Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine The NFA sets the fine at $10,000, but the general federal sentencing statute permits fines up to $250,000 for any felony unless the underlying law opts out, and the NFA does not.
The Gun Control Act separately criminalizes possessing or transferring any machinegun not lawfully owned before the May 1986 cutoff, with penalties up to ten years and a fine up to $250,000.12Office of the Law Revision Counsel. 18 USC 924 – Penalties Penalties apply per violation, so multiple unregistered firearms can produce stacked charges.
State violations sit on top. Possession in a state that bans machineguns brings separate state charges, and both governments can prosecute the same conduct as separate sovereigns without triggering double jeopardy. In practice, prison time is the norm rather than the exception in these cases.
Bump Stocks and Rate-of-Fire Devices
Because the legal definition turns on mechanical function rather than how fast a gun fires, devices that speed up a semiautomatic rifle without meeting the statute occupy contested ground. Bump stocks are the clearest example. They use recoil to help a shooter’s finger pull the trigger in rapid succession, imitating automatic fire without altering the weapon’s mechanics. The ATF classified them as machineguns in 2018, but the Supreme Court struck that classification down in 2024. In Garland v. Cargill, the Court held that a semiautomatic rifle equipped with a bump stock is not a machinegun under the statute because each shot still requires a separate function of the trigger and the shooter must actively maintain forward pressure to sustain fire.13Supreme Court of the United States. Garland v. Cargill, 602 U.S. 406 (2024) Congress has considered but not passed a separate ban.14Bureau of Alcohol, Tobacco, Firearms and Explosives. Bump Stocks
Forced reset triggers went through a similar fight. A 2025 Department of Justice settlement resolved the ATF’s earlier position, and FRTs that require a separate trigger pull for each shot are not machineguns under federal law. Several states independently ban bump stocks, FRTs, or both, so federal legality doesn’t guarantee legality where you live.