Short-barreled rifle (SBR) is a legal designation in the United States, referring to a shoulder-fired, rifled firearm, made from a rifle, with a barrel length of less than 16 in (41 cm) or overall length of less than 26 in (66 cm), or a handgun fitted with a buttstock and a barrel of less than 16 inches length. In the United States, an SBR is an item regulated by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) as a Title II weapon. In the absence of local laws prohibiting ownership, American civilians may own an SBR provided it is registered with the ATF, and a $200 tax is paid prior to taking possession of or creating the firearm.
Overall length is measured between the extreme ends of the gun, along a centerline which passes through the middle of the barrel. For rifles fitted with folding or telescoping stocks (such as U.S. Carbine M1A1), US Federal guidelines state that measurement is performed with the stock unfolded as intended for use as a rifle. Some states — such as California and Michigan — measure overall length with the stock folded. Barrel length is measured from the end of the muzzle to the front of the breechface, typically by inserting a measuring rod into the barrel. Barrel length may partially comprise a permanently attached muzzle accessory (such as a recoil compensator or flash suppressor).
Short barreled rifles can be created through end-user modification by trimming down a larger rifle, by building a rifle with an original barrel shorter than 16 in (41 cm), or by adding a shoulder stock to a handgun which is fitted with a barrel shorter than 16 in (41 cm), which would legally redefine it as a rifle rather than a handgun. Each of these processes must legally be accompanied by ATF registration.
Some older handguns, such as the original broomhandle Mausers or Lugers manufactured before 1946, may be considered relics instead of weapons, and not regulated by federal SBR rules; however, they may still be subject to local laws. The ATF maintains a list of Curio & Relic of gun models and serial number ranges. While they are not considered firearms under the 1934 National Firearms Act, they are regulated by the Gun Control Act of 1968.
In the United States, it is a federal felony to possess an SBR unless it is registered with the ATF to the person who possesses it. Class 2 manufacturers, Class 3 dealers, and government agencies can transfer these firearms, tax exempt. The individual buyer or owner is responsible for paying the $200 tax when purchasing, manufacturing, or transferring an SBR. They must also notify the ATF when transporting it across state lines.
As a result of the Supreme Court decision in United States v. Thompson/Center Arms Company, 504 U.S. 505 (1992), it is not illegal to possess a "kit" allowing a handgun to be fitted with a buttstock and with barrels both under and over the 16 inch minimum for a rifle, so long as the firearm is only assembled into legal (handgun with no buttstock, rifle with buttstock and 16 inch or longer barrel) configurations. Assembling the firearm into an NFA-regulated configuration (rifle with buttstock but barrel shorter than 16 inches) would be a violation of the National Firearms Act.
Canadian regulations include among prohibited weapons firearms adapted from a rifle by sawing, cutting or any other alteration to an overall length less than 660 mm (26 in) or a barrel length less than 457 mm (18.0 in).
Legally, most Australian legislation prescribes a minimum allowable barrel length which is typically about 330 mm (13 in) for rifles.
- ATF (ed.). Federal Firearms Regulations Reference Guide. Washington, D.C.: DIANE Publishing. ISBN 978-1-4289-5186-0.
- "US Code, TITLE 18 > PART I > CHAPTER 44 > § 921 > a > 8".
- ATF Curio and Relic List.
- Sweeney, Patrick (13 February 2014). Gunsmithing - The AR-15. Krause Publications. p. 244. ISBN 978-1-4402-3848-2.
- "Classes of Firearms". Royal Canadian Mounted Police. Retrieved 14 July 2020.
- Home Office (2002). Firearms Law Guidance to the Police. London: The Stationery Office. p. 9.
- Smith, Geoff. "The handgun in Australia today". Sporters Shooting Association of Australia. Retrieved 14 July 2020.