How to Legally Purchase and Register a Short-Barreled Rifle

To legally purchase and register a short-barreled rifle, you file ATF Form 4 with the Bureau of Alcohol, Tobacco, Firearms and Explosives, pass a federal background check, notify your local chief law enforcement officer, and wait for the NFA Division to approve the transfer before your dealer hands over the firearm. The National Firearms Act transfer tax for SBRs is currently $0 under federal statute, though the paperwork itself is unchanged.¹ Possessing an unregistered SBR is a federal felony punishable by up to ten years in prison, so every step matters more than speed.²

Confirm Your State Allows SBR Ownership

Federal approval means nothing if your state bans short-barreled rifles. A handful of states and the District of Columbia prohibit civilian SBR ownership outright, and several others impose restrictions beyond federal law. Check your state’s firearms statutes or contact your state police before you spend time on the ATF application. Moving to a state that bans SBRs after you have registered one creates its own legal problem, so think about the long term as well.

Who Can Legally Own One

You must be at least 21 to purchase an SBR from a licensed firearms dealer. Federal law also bars several categories of people from possessing any firearm, including NFA items. If any of the following apply, you cannot legally own an SBR:³

A felony conviction, meaning any crime punishable by more than one year of imprisonment, whether or not you served time.
A misdemeanor domestic violence conviction, or an active restraining order that includes a finding of credible threat to an intimate partner or child.
Being an unlawful user of, or addicted to, any controlled substance.
Having been formally adjudicated as mentally defective or involuntarily committed to a mental institution.
A dishonorable discharge from the Armed Forces.
Having renounced U.S. citizenship.
Being a fugitive from justice.
Being unlawfully in the United States or, in most cases, admitted on a nonimmigrant visa.

The ATF runs a thorough background check during the application process, and any disqualifier will result in denial.

Buying an SBR vs. Building One

There are two paths, each using a different form. Which one you use decides which form you file, but both go through the same background check, CLEO notification, and federal registration.

Use ATF Form 4 when you buy a factory-built SBR from a licensed dealer. The dealer holds the firearm while your application is processed. This is the most common route for first-time NFA buyers.

Use ATF Form 1 when you want to convert an existing firearm into an SBR yourself, typically by installing a shorter barrel on a rifle or adding a stock to a pistol. You must receive ATF approval before making any modifications.

The NFA tax for transferring or making an SBR is currently $0 under federal statute.⁴ ATF forms may still reference a $200 tax from the prior rate schedule; the statutory rate for SBRs is $0 because they are classified separately from machineguns and destructive devices.

Register as an Individual or Through a Trust

Before filing, decide whether the SBR will be registered to you as an individual or to an NFA trust. This choice controls who can legally touch the firearm and what happens to it when you die.

Register as an individual and only you can possess or have access to the SBR. No one else should have the combination to the safe it sits in, and you need to be physically present whenever someone else handles it. If you die, the executor of your estate files ATF Form 5 to transfer the SBR to a lawful heir.

An NFA trust lets you name multiple trustees, called “responsible persons,” who can each legally possess and transport the firearms the trust holds. A spouse, adult child, or shooting partner listed as a co-trustee can access the SBR without you being present. The trust also simplifies inheritance because successor trustees and beneficiaries are named in the trust document. The trade-off: every responsible person on the trust must individually submit fingerprints, photographs, and undergo a background check with each new NFA application.⁵

What to Gather Before You File

Have everything in hand before you touch the form. A missing item delays the application or gets it rejected.

Your full legal name, current address, date and place of birth, and Social Security number.
The SBR’s make, model, caliber, serial number, barrel length, and overall length. Your dealer can provide this for a factory SBR.
Two completed FBI Form FD-258 fingerprint cards. Local law enforcement agencies, UPS stores, and private fingerprinting services can roll these; the ATF eForms system also accepts digital fingerprint files.
Two passport-style photos, approximately 2×2 inches.
The name, address, and Federal Firearms License number of the transferring dealer, for Form 4 purchases.
If filing through a trust, a copy of your NFA trust agreement plus a completed ATF Form 5320.23 for each responsible person named in the trust.⁵

Dealers who regularly handle NFA transfers can walk you through the form and will typically charge a transfer or processing fee for their part.

Filing the Application

Submit ATF Form 4 either as a paper application mailed to the NFA Division or electronically through the ATF eForms system.⁶ Electronic filing is faster in every measurable way, and most dealers now default to eForms and will guide you through the digital submission.

For paper submissions, the transferring dealer sends two copies to the NFA Division in Martinsburg, West Virginia.⁷ Check every field twice. A typo in the serial number or a missing signature gets the application kicked back and starts the wait over.

CLEO Notification

Federal law requires you to send a copy of the completed application to the chief law enforcement officer in your jurisdiction, which is the local chief of police, county sheriff, or district attorney. The CLEO does not need to approve or sign anything. The requirement is notification only, and the form itself tells the CLEO no action is needed, though they may contact the NFA Division if they have disqualifying information about you.⁷ If you file through a trust, each responsible person must also send a copy of their completed Form 5320.23 to their respective CLEO.

How Long Approval Takes

Processing times have improved from the months-long waits that were once standard. As of February 2026, the ATF reports these average processing times for Form 4:⁸

Individual eForms: 10 days average
Individual paper: 21 days average
Trust eForms: 26 days average
Trust paper: 24 days average

These are averages. Some applications clear faster; others take longer when the background check flags something that needs additional research. For Form 1 applications in the same period, eForms averaged 36 days and paper averaged 20 days.⁸

When the ATF approves the application, they return the approved Form 4 with an affixed tax stamp to your dealer. The dealer then contacts you for pickup and runs a final background check through the National Instant Criminal Background Check System before handing you the firearm. Keep a secure copy of the approved form and tax stamp; you will need it as proof of registration for as long as you own the SBR.

Engraving Requirements for Form 1 Builds

Building your own SBR under a Form 1 triggers an engraving requirement. Before, or immediately upon, completing the modification, federal regulations require you to engrave specific identifying information on the frame or receiver: your name, the city and state where you made the firearm, a unique serial number, the caliber, and the model designation if applicable.⁹

The engraving must be at least .003 inches deep, with the serial number printed no smaller than 1/16 inch as measured from the base of the characters. Many builders use a local engraving shop that specializes in firearms. Skipping the step or using markings that do not meet the depth and size requirements puts you in violation of federal law.

Traveling, Storage, and Proof of Registration

An SBR is not treated like a standard rifle once you own it. Federal law prohibits transporting a short-barreled rifle in interstate commerce without prior written authorization from the ATF, whether you are driving to an out-of-state range for a weekend or permanently relocating.³ The form for this is ATF Form 5320.20, which asks for the reason for transport, the firearms involved, and the origin and destination. For temporary trips you specify dates; for a permanent move you check “Permanent change of address.” Submit the form to the NFA Division by mail, fax, or email and wait for approval before crossing the state line.¹⁰ ATF approval to transport does not override a state-level ban, so confirm SBR ownership is legal in your destination before filing.

Who can physically reach your SBR matters too. If the firearm is registered to you as an individual, you are the only person authorized to possess it. Leaving it in an unlocked case where a spouse, roommate, or anyone else can access it while you are away could put them in constructive possession of an unregistered NFA firearm, which is a federal crime for them, not just for you.¹¹ The practical fix is a safe or locked container that only you can open. If you registered through an NFA trust, any responsible person named on the trust can legally access and possess the firearms the trust holds, which avoids the scenario where a family member unknowingly commits a felony.

Federal law also requires you to retain proof that your SBR is registered in the National Firearms Registration and Transfer Record and to produce it for any ATF officer who asks.¹² Your approved Form 4 (or Form 1) with the affixed tax stamp is that proof. Make high-quality copies or scans and store them in more than one place: a fireproof safe at home, a secure cloud account, and with the firearm when you transport it. The original approved form is irreplaceable if lost, and a duplicate from the ATF comes with its own wait.

Penalties for Getting It Wrong

The consequences for NFA missteps are federal and severe. Possessing an unregistered SBR, transferring one outside the approved process, or making one without prior ATF approval are all felonies. A conviction carries a fine of up to $10,000, up to ten years in prison, or both.² That penalty applies equally to someone who never filed a form and someone who assembled a Form 1 build before approval came back. The ATF does not distinguish between intentional evasion and procedural mistakes when charging decisions get made, so treat every step of this process as mandatory.

1
Office of the Law Revision Counsel. 26 USC 5811 – Transfer Tax
2
Office of the Law Revision Counsel. 26 USC 5871 – Penalties
3
Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts
4
Office of the Law Revision Counsel. 26 USC 5821 – Making Tax
5
Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act (NFA) Responsible Person Questionnaire
6
Bureau of Alcohol, Tobacco, Firearms and Explosives. eForms Applications
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. Current Processing Times
9
eCFR. 27 CFR 479.102 – Identification of Firearms
10
Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transport Interstate or to Temporarily Export Certain National Firearms Act (NFA) Firearms
11
Office of the Law Revision Counsel. 26 USC 5861 – Prohibited Acts
12
Bureau of Alcohol, Tobacco, Firearms and Explosives. Federal Firearms Licensee Quick Reference and Best Practices Guide