Disclaimer: I am not a lawyer; no one in this office is a lawyer. This information is based on personal experience and research. Before you do anything involving SBRs, make sure you contact the local ATF Division about SBR laws in your state.


Maxim Defense SBR MDX:508
Photo Credit: Maxim Defense | MDX:508 (Rifle)

What is a SBR?

SBR stands for short barrel or short-barreled rifle, and it’s classified as anything shorter than 16-in. or anything made from a rifle, with an overall length less than 26-in.

Of course, there are plenty of regulations around this particular type of firearm, more or less, depending on where you live. And while it’s not hard to get, you’ll have to gain a tax stamp if you want to build or purchase a SBR.


“…an NFA firearm is made if aggregated parts are in close proximity such that they: (a) serve no useful purpose other than to make an NFA firearm (e.g., a receiver, an attachable shoulder stock, and a short barrel); or (b) convert a complete weapon into an NFA firearm (e.g., a pistol and attachable shoulder stock, or a long-barreled rifle and attachable short barrel). Id. at 511-13.”

-ATF Regulation

Basically, according to the ATF, if you don’t have a tax stamp, but you have the ability to build an NFA regulated firearm, such as a SBR, and the parts are in close proximity to making such weapon(s), you are violating federal regulations, but only if those parts serve no other purpose.

I draw your attention to “no other purpose” because another purpose is partially why the Supreme Court ruled in favor of Center Arms Co., which I’ll get to shortly.

Basically, anyone can own an SBR IF you can acquire a tax stamp. Unfortunately, not everyone will get approved for a tax stamp, depending on where you live, which we’ll get to here in a bit as well.

Of course, the same laws apply when it comes to purchasing a firearm in general. For example, if you’re a felon, you aren’t getting one. And if you’re in possession of a SBR without the tax stamp, congratulations, you’ve now committed a felony (unless you’re exempt).

If you qualify for a tax stamp, you’ll have to pay $200 before purchasing or assembling a SBR.

How to get a tax stamp for SBR

If you want to obtain a tax stamp for a SBR, you’ll have to file the form that applies to you, which could take weeks, months, or even a year, depending on how you file and how quickly things are being processed.

Maxim Defense SBR MDX 510
Photo Credit: Maxim Defense | MDX: 510 (Rifle)
  • ATF Form 1: Required for the manufacturing of a firearm
  • ATF Form 4: Required when transferring the item from a dealer to the final buyer

Key Terms

Below are some key terms you’ll need to know when it comes to the legalities of SBRs.

Crude Manufacture

A crude manufactured weapon is one in which the barrel is less than 18-in. and/or the overall length is less than 26-in, the stock is altered, barrel cut down. Ultimately, the overall length determines if the weapon is crudely manufactured or not when the barrel has been cut down.  If the weapon’s overall length is at least 26-in and the barrel is less than 18-in, it can still be classified as a firearm.


“Any weapon, including a starter gun, which will or is designed to or may readily be converted to expel a projectile by the action of an explosive; the frame or receiver of any such weapon; any firearm muffler or firearm silencer; or any destructive device; but the term shall not include an antique firearm. In the case of a licensed collector, the term shall mean only curios and relics.”

-Federal Firearms Act. 15 U.S.C. Chapter 18

Weapon Made from a Rifle

A weapon made from a rifle is one in which the length is less than 26-in or a barrel less than 16-in.

Curios or Relics

Curios or relics or C&R are firearms that are of particular interest to collectors for something other than sports, offensive, or defensive weapon use. Some states do not authorize SBR ownership/use but do authorize C&R ownership.

To be considered as curios or relics, the firearm must fall into one of the below categories, per the ATF:

(a) Firearms which were manufactured at least 50 years prior to the current date, but not including replicas thereof;

(b) Firearms which are certified by the curator of a municipal, State, or Federal museum which exhibits firearms to be curios or relics of museum interest; and

(c) Any other firearms which derive a substantial part of their monetary value from the fact that they are novel, rare, bizarre, or because of their association with some historical figure, period, or event. Proof of qualification of a particular firearm under this category may be established by evidence of present value and evidence that like firearms are not available except as collector’s items, or that the value of like firearms available in ordinary commercial channels is substantially less.

Important Firearm Acts and Cases

NFA: National Firearms Act of 1934

According to the ATF, the NFA of 1934 imposed a tax on making and transferring firearms that fell under the NFA. It also imposed an occupational tax on those who engage in the business of importing, manufacturing, and dealing with NFA firearms.

The law also requires that all weapons falling under the NFA must be registered with the Secretary of the Treasury.

Furthermore, the NFA’s underlying purpose was to make it difficult to own NFA classified firearms, which is where the $200 tax stamp came into play because, at the time, $200 was considered a significant purchase price, impossible for many. However, this price has not changed since 1934.

GCA: Gun Control Act of 1968

The gun control act was put into place after President Kennedy and MLK’s assassination. This act intended to make licensing more strict and create more regulations within the firearm industry. The GCA also created new categories of firearm offenses and made it illegal to sell firearms or ammunition to felons. Furthermore, it created the first Federal Jurisdiction over destructive devices.

United States v. Thompson/Center Arms Company

You can read the entire case here: US v. Thompson/Center Arms Co. 

But, for the purpose of ease, here’s a quick synopsis. The Center Arms Co. sold a kit. In the kit, one could assemble a pistol or a rifle. However, if the user assembled the rifle stock but failed to remove the 10-in barrel and replace it with the 21-in barrel, they would have a SBR and violate the NFA since no tax stamp was acquired to transfer or buy this variation.

The case was ruled in favor of the Center Arms Co. because of the ambiguity. There was no way of proving the intent of creating a SBR, and because the user was capable of creating a rifle, by definition, greater than 16-in, Center Arms Co. won. Basically, there was a purpose OTHER than building a SBR.

“A firearm, as defined by 26 U.S.C. 5845(a)(3) and (a)(4), is not made when parts within a kit that were originally designed to be configured as both a pistol and a rifle are assembled or re-assembled in a configuration not regulated under the NFA (e.g., as a pistol, or a rifle with a barrel or barrels of 16 inches or more in length).”

-ATF Regulations

Rule of Lenity/Rule of Strict Construction

As mentioned above, the court case won due to ambiguity. This was because there was a failure to prove intent to fire the short barrel from a shoulder-fired position, and they found a purpose other than building a SBR.

Maxim Defense MD 15 SBR
Photo Credit: Maxim Defense | MD:15 (AR Pistol)


Photo Credit: Maxim Defense | MD:15 (SBR)


Rule of Lenity, also called Rule of Strict Construction, requires a criminal court to apply unclear or ambiguous law in a way that is most favorable for the defendant. Because Center Arms Co.’s case was ambiguous, that ambiguity was applied in a way that was most favorable to them, the defendant.

SBR Laws by State

If you’re looking for more details, here are the most up-to-date pieces of information on SBR laws by state, as published by the ATF.

For more general definitions, as it pertains to the NFA, you can read the classifications of firearms.

You can even read about the transfer of NFA firearms if you think it might apply to you.

And just a heads up, some state publications are a little confusing about what is and isn’t allowed. When you follow the SBR laws by state link on ATF’s website, call the number listed for your state to get further clarification.

There are a lot of bloggers out there who have outdated information, and some are just flat-out wrong, no matter when they published. Your best option, for the purpose of legalities, is to call your state’s authority.

If SBRs are authorized in your state, you can then apply for a tax stamp.

Owning a SBR

Whether you’re looking to build a SBR in your home or purchasing from a qualified dealer, there are a few things you need to know, such as which forms to fill out.

  • ATF Form 1: Required for the manufacturing of a firearm
  • ATF Form 4: Required when transferring the item from a dealer to the final buyer

Building a SBR

You can build your own SBR, right in your home (If you get your tax stamp). This would include something such as taking an AR-15 style firearm and putting a 10-in barrel on it. Again, you have to get your tax stamp first for this to be legal.

Purchasing a SBR

You can also purchase a pre-fabricated SBR. Again, you’ll have to apply for your tax stamp prior, and then show you have it before buying this type of weapon.

Disclaimer: Again, I am not a lawyer; no one in this office is a lawyer. This information is based on personal experience and research. Before you do anything involving SBRs, make sure you contact the local ATF Division about SBR laws in your state.

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