Under federal law, a short-barreled rifle is any rifle with a barrel shorter than 16 inches or an overall length under 26 inches, and it falls under the National Firearms Act. That means you cannot make one or buy one without first registering it with ATF and passing a background check. The one thing that has changed is cost: the making and transfer tax on an SBR is now $0, replacing the $200 stamp that defined NFA ownership for decades. Everything else about how short-barreled rifles are regulated under federal law, including the paperwork, the possession rules, and the penalties, remains in force.
What Counts as a Short-Barreled Rifle
The definition sits in 26 U.S.C. § 5845. A rifle is a shoulder-fired weapon that uses an explosive cartridge to fire a single projectile through a rifled bore.1Office of the Law Revision Counsel. 26 USC 5845 – Definitions A rifle becomes an NFA-regulated short-barreled rifle in either of two situations:
- Its barrel is under 16 inches, measured from the closed bolt or breech face to the farthest end of the barrel or any permanently attached muzzle device.
- Its overall length is under 26 inches, even if the barrel itself clears 16 inches.
The same thresholds apply to any weapon “made from a rifle,” meaning a full-length rifle cut down or reconfigured to fall below either measurement.2Office of the Law Revision Counsel. 26 USC 5845 – Definitions A muzzle device counts toward barrel length only if it’s permanently attached by full-fusion welding, high-temperature silver soldering at 1,100°F or higher, or blind pinning with the pin welded over.3Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act Handbook A flash hider you can spin off by hand doesn’t. A 14.5-inch barrel with a properly pinned-and-welded device bringing it to 16 inches is not an SBR.
Check Your State’s Law First
Federal approval doesn’t override a state ban. Several states prohibit civilian SBR possession outright regardless of NFA registration, and others impose their own permits or restrictions. ATF will approve your Form 1 or Form 4 even if you live in a state where the firearm is illegal, and you’ll be committing a state felony the moment you take possession. Confirm your state’s law before you start any federal paperwork.
The Tax Is Now $0, But Registration Still Applies
Under the current text of 26 U.S.C. § 5811 and § 5821, the $200 making and transfer tax applies only to machineguns and destructive devices. Short-barreled rifles, short-barreled shotguns, and silencers now carry a $0 tax.4Office of the Law Revision Counsel. 26 USC 5811 – Transfer Tax5Office of the Law Revision Counsel. 26 USC 5821 – Making Tax
The tax going to zero did not end the registration requirement. You still must submit the correct ATF form, receive approval, pass a background check, and comply with every documentation and possession rule that applied when the stamp cost $200.
Form 1 or Form 4: Which Application You File
The form depends on what you’re doing.
ATF Form 1 (Application to Make and Register a Firearm) is for anyone making an SBR from an existing receiver, pistol, or rifle. Making includes shortening a barrel, adding a stock to a pistol-caliber receiver, or any assembly or alteration that produces a rifle with a barrel under 16 inches. You must have ATF approval in hand before you do any of that work. Assembling first and paperwork later is a federal crime.6Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 5320.1 – Application to Make and Register a Firearm
ATF Form 4 (Application for Tax Paid Transfer and Registration of Firearm) is for acquiring an SBR that already exists as a registered NFA firearm, whether from a dealer, another individual, or a trust. The firearm does not change hands until ATF approves the application.7Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 5320.4 – Application to Transfer and Register NFA Firearm
Both forms take the manufacturer, model, serial number, and caliber. Both can be filed through ATF’s eForms portal or by mailing a paper application to the NFA Branch in Martinsburg, West Virginia. eForms is much faster. As of early 2026, individual Form 4 eForms applications regularly clear in under a month, with some approvals returning in days.8Bureau of Alcohol, Tobacco, Firearms and Explosives. Current Processing Times Trust and corporate applications run somewhat longer because ATF processes paperwork for each responsible person.
What You Submit With the Application
Every applicant, and every responsible person for a trust or entity, must provide:
- A 2×2-inch color frontal photograph taken within the past year.
- Two completed FBI Form FD-258 fingerprint cards. Smudged prints can kill an application; local law enforcement, UPS stores, and private fingerprinting services typically charge $30 to $150 to produce good cards.
- A copy of the completed form sent to your local Chief Law Enforcement Officer, meaning the chief of police, sheriff, head of state police, or local district attorney. This is notification only. The CLEO does not sign off or approve anything.
ATF’s 2016 Rule 41F changed the CLEO step from a signature requirement into a notification requirement for individuals, and it extended the notification (along with fingerprints and photos for responsible persons) to trusts and corporations.6Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 5320.1 – Application to Make and Register a Firearm
Engraving the Receiver When You Build One
If you’re making an SBR on a Form 1, you must permanently mark the receiver before or at the time of making it. Federal regulations require your full legal name (or a recognized abbreviation), the city and state where you made it, a unique serial number that doesn’t duplicate any serial on your other firearms, and the caliber. Markings must be at least 1/16 inch in print size and .003 inch deep, in Roman letters and Arabic numerals, and legible during normal handling.9eCFR. 27 CFR 479.102 – Identification of Firearms Most builders hire a professional engraver rather than risk shallow or unreadable marks.
Trusts and Who Else Can Handle the Firearm
An SBR registered to you as an individual can only be possessed by you. If your spouse or a friend handles it while you’re not physically present, they are in possession of an NFA firearm not registered to them, which is a federal felony. An NFA trust solves this by letting multiple trustees legally possess and use the firearm.
A trust names responsible persons: anyone with authority to direct the trust’s management or handle its firearms. That includes the settlor, all trustees, and any other person with authority over trust property. Each responsible person must submit their own fingerprints, photograph, completed ATF Form 5320.23 (Responsible Person Questionnaire), and CLEO notification.10Bureau of Alcohol, Tobacco, Firearms and Explosives. ATF Form 5320.23 – National Firearms Act Responsible Person Questionnaire Beneficiaries who cannot direct the trust or handle firearms are typically not responsible persons and don’t file paperwork.
A trust also smooths inheritance, since it survives the settlor’s death and successor trustees can step in without the firearm sitting in a legal gray zone during probate. A properly drafted NFA trust from a qualified attorney typically runs several hundred dollars, and every trustee must be legally eligible to possess firearms under both federal and state law. Generic online templates are risky; a poorly drafted trust can be unenforceable.
Possession Rules and Penalties
The NFA’s list of prohibited acts is long. Federal law makes it illegal to possess an NFA firearm not registered to you, to make or transfer one outside the required procedures, to obliterate or alter the serial number, or to transport one across state lines without authorization, among other violations.11Office of the Law Revision Counsel. 26 USC 5861 – Prohibited Acts
Conviction for any NFA violation carries up to 10 years in federal prison and a fine of up to $250,000.12Office of the Law Revision Counsel. 26 USC 5871 – Penalties13Office of the Law Revision Counsel. 18 USC 3571 – Sentence of Fine The firearm itself is subject to seizure and forfeiture. The penalties are the same whether you intentionally circumvented the law or simply didn’t realize your build met the SBR definition.
The registered owner must retain proof of registration and produce it to ATF on request.14Office of the Law Revision Counsel. 26 USC 5841 – Registration of Firearms Keep both a digital and a printed copy of your approved form, and carry one with the firearm.
Constructive Possession
You don’t have to finish assembling an unregistered SBR to be prosecuted. Federal courts have held that owning all the parts needed to build a restricted firearm can amount to possession of that firearm. In United States v. Thompson/Center Arms Co. (1992), a plurality of the Supreme Court applied an “obvious utility” test: if the parts have a legitimate legal use, such as fitting a registered SBR you already own, mere proximity may not create a violation. If you own a short upper and a rifle lower with no registered SBR on file, the risk is real. The safest practice is to not acquire SBR-length components until your Form 1 is approved.
Taking a Short-Barreled Rifle Across State Lines
Federal law forbids transporting an SBR across state lines without prior ATF authorization.15Office of the Law Revision Counsel. 18 USC 922 – Unlawful Acts Before the firearm leaves its registered state, you file ATF Form 5320.20 identifying the firearm, the destination, and the travel dates, and you must have approval in hand before you go.16Bureau of Alcohol, Tobacco, Firearms and Explosives. Application to Transport Interstate or to Temporarily Export Certain NFA Firearms
The requirement covers short-barreled rifles, short-barreled shotguns, machineguns, and destructive devices. Silencers are exempt from the interstate transport approval requirement, which catches people who assume every NFA item follows the same rule. A permanent move to another state also requires a new 5320.20, and you should confirm the destination state permits SBRs before shipping or transporting the firearm.
Passing an SBR On When You Die
When the owner dies, the executor or administrator of the estate takes temporary custody. ATF allows a reasonable time to arrange a proper transfer, and that transfer generally should be completed before probate closes.17Bureau of Alcohol, Tobacco, Firearms and Explosives. Transfers of National Firearms Act Firearms in Decedents’ Estates
Transfers to a lawful heir, meaning anyone named in the will or entitled under state intestacy law, are tax-exempt. The executor files ATF Form 5 (Application for Tax Exempt Transfer and Registration of Firearm) on the heir’s behalf. The heir still must pass a background check and be legally eligible to possess firearms.18Bureau of Alcohol, Tobacco, Firearms and Explosives. National Firearms Act Handbook
Two traps recur. First, handing the firearm to a dealer or anyone else for safekeeping during probate is itself an illegal transfer. Second, if the estate contains an NFA firearm that was never registered or whose registration can’t be verified, the firearm is contraband. It cannot be registered after the fact. The executor should contact the local ATF field office to arrange abandonment rather than risk a possession charge.17Bureau of Alcohol, Tobacco, Firearms and Explosives. Transfers of National Firearms Act Firearms in Decedents’ Estates