How to Legally Own a Machine Gun: Form 4, Trusts, and Approval

To legally own a machine gun as a private citizen in the United States, you have to buy one that was manufactured and registered with the federal government before May 19, 1986, purchase it through a specially licensed dealer, and get the transfer approved by the ATF after a background check, fingerprint submission, and payment of a $200 federal tax. Your state must also permit civilian machine gun ownership, because federal approval does not override a state ban. Expect the firearm itself to start around $7,000 for common models and run past $30,000 for desirable ones, because the civilian supply has been frozen for nearly four decades.

The freeze comes from the Firearm Owners’ Protection Act of 1986. A provision known as the Hughes Amendment made it illegal for any private citizen to possess or transfer a machine gun that was not already lawfully registered before May 19, 1986.¹ Newer machine guns exist, but only government agencies and certain licensed dealers can acquire them.² Everything below assumes you are buying from the fixed pool of pre-1986 transferable firearms.

Check Your State Law Before Anything Else

Federal law gives you a path. Your state can close it. Roughly 17 states and the District of Columbia prohibit private machine gun possession outright, including California, New York, New Jersey, Illinois, and Hawaii. Others allow possession but layer on additional requirements. About nine states add nothing beyond federal law.

If your state bans them, an approved ATF Form 4 will not protect you. You would be committing a state crime the moment the dealer handed you the firearm. Confirm state and local law before you spend a dollar or a minute on the federal process.

Who Can Legally Buy One

You must be at least 21 to purchase an NFA firearm from a licensed dealer.³ You must be a legal resident of the state where the transfer occurs. And you must not fall into any federally prohibited category. You are barred from ownership if you:

Have been convicted of a crime punishable by more than one year in prison
Are a fugitive from justice
Are a regular, ongoing user of a controlled substance
Have been found mentally defective by a court or committed to a mental institution
Were dishonorably discharged from the military
Have renounced U.S. citizenship
Have certain domestic violence convictions or active restraining orders

The controlled-substance prohibition changed in January 2026. A Department of Justice interim rule now requires evidence of “regular and recent use” before someone is treated as an unlawful drug user, and the old inference tests (like a single arrest or positive drug test within the past year) have been removed.⁴ Marijuana still counts. It remains a Schedule I controlled substance under federal law, so regular use disqualifies you even if your state has legalized it.

Find a Class 3 Dealer and a Transferable Gun

Civilian machine gun transfers must go through a federally licensed dealer who has paid the NFA Special Occupational Tax, commonly called a Class 3 or SOT dealer.⁵ The dealer holds the firearm while your application is processed and typically charges a transfer fee of $100 or more on top of the sale price.

Prices reflect the frozen supply. A MAC-style submachine gun might come in under $10,000. A transferable M16 lower receiver routinely exceeds $30,000. If a listing looks cheap for a full-auto weapon, assume something is wrong with the listing or the legality before assuming you found a bargain.

Under federal law, a machine gun is any weapon that fires more than one round with a single pull of the trigger without manual reloading. The definition also covers the frame or receiver of such a weapon and any part or combination of parts designed to convert a semi-automatic gun to fire automatically.⁶ That means conversion devices like registered pre-1986 auto sears are themselves machine guns for legal purposes and follow the same transfer rules.

Decide Between Individual Registration and a Gun Trust

Before filing paperwork, choose how the firearm will be registered. The choice has real consequences.

Individual registration is simpler. You file, you get approved, and you are the only person who can legally possess the firearm. Nobody else can use it, transport it, or access your safe unless you are present. A spouse pulling it out while you are away is a federal violation.

A gun trust lets multiple trustees legally possess the firearm. That solves the family-access problem and simplifies inheritance, because the trust survives your death and can pass the item to beneficiaries without going through the standard transfer process. The tradeoff: every trustee, called a “responsible person,” has to submit fingerprints, photographs, and pass a background check.⁷ You also need a signed trust document, which typically costs a few hundred dollars through an attorney or an NFA-focused service.

File ATF Form 4

The core application is ATF Form 4, “Application for Tax Paid Transfer and Registration of Firearm.”⁸ It captures information about the buyer, the seller, and the specific firearm, including manufacturer, model, caliber, and serial number.

With the form, you submit two passport-style photographs and two completed FBI fingerprint cards (Form FD-258). If a trust is buying, every responsible person listed on the trust submits their own photos and fingerprints, and a complete copy of the signed trust document goes with the application.⁷

You are also required to send a copy of the completed Form 4 to the chief law enforcement officer with jurisdiction over your address. This is a notification. The CLEO does not have veto power over your application.⁷

At submission you pay the $200 federal transfer tax. The amount has not changed since 1934. Payment goes through credit card, debit card, or pay.gov. When ATF approves, it affixes a tax stamp to your Form 4, and the stamped form is your legal proof of registration.⁷

File electronically through the ATF eForms system whenever possible. Paper filings are still permitted but process far more slowly, and there is little reason to use them unless you cannot access the online system.

How Long Approval Takes

Wait times have dropped sharply. As of January 2026, the ATF reports average eForm 4 processing times of 10 days for individuals and 11 days for trusts.⁹ That is a significant change from the multi-month and year-long waits common before the electronic system matured. Paper applications still lag well behind. Once the ATF approves, the stamped Form 4 goes back to the dealer, who can then release the firearm to you.

What You Have to Do After You Take Possession

Approval starts a set of ongoing obligations. Ignoring them can turn a lawful owner into a felon.

Keep Proof of Registration With the Firearm

You must retain proof of registration and make it available to any ATF officer who asks.⁷ In practice, keep the original stamped Form 4 in your safe and a clear copy with the firearm whenever you transport it.

Get Written Approval Before Crossing State Lines

You cannot simply drive a machine gun across a state border. File ATF Form 5320.20 and get written approval before transporting the firearm interstate. The form asks you to specify the dates the firearm will be away from its registered location and to certify that possession at the destination does not violate local law.¹⁰ If you do not return the firearm by the date you listed, file a new application. The form can be submitted by mail, fax, or email to the NFA Division.

Report Theft or Loss Immediately

Federal regulations require licensed dealers to report a stolen or lost NFA firearm within 48 hours of discovery by calling ATF and filing a theft/loss report on Form 3310.11, with a separate report to local police.¹¹ As an individual owner, reporting promptly to ATF and local law enforcement protects you from liability if the firearm later shows up in a crime.

Penalties for Getting It Wrong

The most common NFA violations are possessing an unregistered machine gun, transferring one without ATF approval, and making false statements on the application.¹² Any NFA violation carries a maximum of 10 years in federal prison, a fine of up to $10,000, or both.¹³

If a machine gun is used in connection with a violent crime or drug trafficking offense, federal law imposes a mandatory minimum of 30 years for a first offense and life imprisonment for a second conviction.¹⁴ These are not theoretical maximums that prosecutors rarely seek. Sentences near the statutory ceiling are common in federal machine gun cases, and the cost of doing the paperwork right is trivial by comparison.

1
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
2
Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act (NFA)
3
Bureau of Alcohol, Tobacco, Firearms and Explosives. Minimum Age for Gun Sales and Transfers
4
Federal Register. Revising Definition of Unlawful User of or Addicted to Controlled Substance
5
Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act (NFA) – Special Occupational Taxes (SOT)
6
Office of the Law Revision Counsel. 26 USC Subtitle E, Chapter 53, Subchapter B, Part I – General Provisions
7
Bureau of Alcohol, Tobacco, Firearms, and Explosives. Application to Transfer and Register NFA Firearm (Tax-Paid) – ATF Form 5320.4
8
Bureau of Alcohol, Tobacco, Firearms and Explosives. Application for Tax Paid Transfer and Registration of Firearms – ATF Form 4 (5320.4)
9
ATF: Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times
10
Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transport Interstate or to Temporarily Export Certain National Firearms Act (NFA) Firearms
11
eRegulations – ATF eRegulations. 27 CFR 478.39a Reporting Theft or Loss of Firearms
12
Office of the Law Revision Counsel. 26 USC 5861 – Prohibited Acts
13
GovInfo. 26 USC 5871 – Penalties
14
Office of the Law Revision Counsel. 18 USC 924 – Penalties