Short-barreled rifle

The term carbine describes a production rifle with a reduced barrel length for easier handling in confined spaces.

Barrel length may partially comprise a permanently attached muzzle accessory (such as a recoil compensator or flash suppressor).

Many older handguns originally designed with shoulder stocks, such as broomhandle Mausers, Lugers, Browning Hi-Power and Inglis as well as many lever action Winchesters with 14 to 15.5 in (36 to 39 cm) barrels, are considered relics instead of NFA restricted, and not regulated by federal SBR rules; however, they may still be subject to local laws.

On 31 January 2023 ATF published a 52-page regulation (Final Rule 2021R-08F) outlining a point-based worksheet of stabilizing brace criteria.

[8] The United States' regulation of short-barreled rifles was the result of the National Firearms Act of 1934 which also imposed restrictions on short barreled shotguns, suppressors and machine guns.

[3] The reasoning for the restrictions on short-barrelled rifles and shotguns was not because they are more dangerous, but rather to prevent circumventing of the act's ban on handguns.

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.

Legally, most Australian legislation prescribes a minimum allowable barrel length which is typically about 330 mm (13 in) for rifles.