Rotating bolt is a method of locking the breech (or rear barrel) of a firearm closed for firing.

Johann Nicolaus von Dreyse Johann Nicolaus von Dreyse (20 November 1787 – 9 December 1867) was a German firearms inventor and manufacturer. He is most famous for submitting the Dreyse needle gun in 1836 to the Prussian army, which was adopted for service in December 1840 ...

developed the first rotating bolt firearm, the "

Dreyse needle gun Dreyse may refer to: * Johann Nicolaus von Dreyse (1787–1867), German firearms inventor * Hitch Dreyse, a fictional List of Attack on Titan characters, character in ''Attack on Titan'' (''Shingeki no Kyojin'') series who serves in the military po ...

", in 1836. The Dreyse locked using the bolt handle rather than lugs on the bolt head like the

Mauser M 98 The Mauser M 98 are a series of currently (2020) produced bolt-action hunting rifles. The production of the controlled round feed Mauser 98 bolt action system for the German military ceased at the end of World War II in 1945. The new Mauser M 98 ...

M16 The M16 (officially Rifle, Caliber 5.56 mm, M16) is a family of assault rifles adapted from the ArmaLite AR-15 rifle for the United States military. The original M16 was a 5.56×45mm automatic rifle with a 20-round magazine. In 1964, th ...

. The first rotating bolt rifle with two lugs on the bolt head was the

Lebel Model 1886 rifle The Lebel Model 1886 rifle (French: ''Fusil Modèle 1886 dit "Fusil Lebel"'') also known as the ''"Fusil Mle 1886 M93"'', after a bolt modification was added in 1893, is an 8 mm bolt-action infantry rifle that entered service in the French A ...

. The concept has been implemented on most firearms chambered for high-powered cartridges since the 20th century.

Design

Ferdinand Ritter von Mannlicher Ferdinand Ritter von Mannlicher (January 30, 1848 – January 20, 1904) was an Austrian engineer and small arms designer. Along with James Paris Lee, Mannlicher was particularly noted for inventing the en-bloc clip charger-loading box magazine s ...

, who had earlier developed a non-rotating bolt straight-pull rifle, developed the

Steyr-Mannlicher M1895 The Mannlicher M1895 (, ; "Infantry Repeating-Rifle M95") is an Austro-Hungarian straight pull bolt-action rifle, designed by Ferdinand Ritter von Mannlicher that used a refined version of his revolutionary straight-pull action bolt, much lik ...

, a straight-pull rifle with a rotating bolt, which was issued to the

Austro-Hungarian Army The Austro-Hungarian Army, also known as the Imperial and Royal Army,; was the principal ground force of Austria-Hungary from 1867 to 1918. It consisted of three organisations: the Common Army (, recruited from all parts of Austria-Hungary), ...

. Mannlicher then developed the M1893 auto rifle which had a screw delayed bolt and later the

Mannlicher M1900 Mannlicher may refer to: * Ferdinand Mannlicher (1848–1904), Austrian engineer and small arms designer, including a list of firearms named after Ferdinand Mannlicher * Steyr Arms Steyr Arms () is a firearms manufacturer based in Austria. Ori ...

operated by a gas piston. This was an inspiration for later

gas operated Gas-operation is a system of operation used to provide energy to operate locked breech, autoloading firearms. In gas-operation, a portion of high-pressure gas from the cartridge being fired is used to power a mechanism to dispose of the spent ...

, semi-automatic and

selective fire Selective may refer to: * Selective school, a school that admits students on the basis of some sort of selection criteria ** Selective school (New South Wales) See also * Selective breeding Selective breeding (also called artificial select ...

firearms (such as the M1, M14,

, the L85A1/A2 and the

AK-47 The AK-47, officially known as the Avtomat Kalashnikova (; also known as the Kalashnikov or just AK), is an assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian small-arms designer Mikhail Kala ...

/ 74) in which the bolt, upon contact with the

breech Breech may refer to: * Breech (firearms), the opening at the rear of a gun barrel where the cartridge is inserted in a breech-loading weapon * breech, the lower part of a pulley block * breech, the penetration of a boiler where exhaust gases leave ...

, rotates and locks into place, the lugs on the bolt locking into the breech or barrel extension. Upon closing, the bolt goes forward into

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden stave (wood), staves and bound by wooden or metal hoops. The word vat is often used for large containers ...

extension or locking recesses in the receiver, and then rotates; at this point it is locked in place. The bolt remains locked until the

action Action may refer to: * Action (philosophy), something which is done by a person * Action principles the heart of fundamental physics * Action (narrative), a literary mode * Action fiction, a type of genre fiction * Action game, a genre of video gam ...

is cycled, either manually by the operator, or mechanically by

delayed blowback Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge. Several blowback systems exist wi ...

recoil operation Recoil operation is an operating mechanism used to implement locked-breech autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action, as opposed to gas operation or blowback operation using the pressure of th ...

, or

gas operation Gas-operation is a system of operation used to provide energy to operate locked breech, autoloading firearms. In gas-operation, a portion of high-pressure gas from the cartridge being fired is used to power a mechanism to dispose of the spent ...

which then rotates the bolt and unlocks it from the breech so that it can be withdrawn in order to extract and eject the spent casing, and the next round can be chambered. In gas operation, the gas port, which meters a portion of the combustion gases into the action in order to cycle the weapon, is typically located either midway down the barrel or near the muzzle of the weapon. In this way it functions as a delay, ensuring that the bolt remains locked until chamber pressure has subsided to a safe level. Rotating bolts are found in

gas-operated Gas-operation is a system of operation used to provide energy to operate locked breech, Semi-automatic firearm, autoloading firearms. In gas-operation, a portion of high-pressure gas from the Cartridge (firearms), cartridge being fired is used t ...

recoil-operated Recoil operation is an operating mechanism used to implement locked-breech autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action, as opposed to gas operation or blowback operation using the pressure of th ...

bolt action Bolt action is a type of manual firearm action that is operated by ''directly'' manipulating the turn-bolt via a bolt handle, most commonly placed on the right-hand side of the firearm (as most users are right-handed). The majority of b ...

lever-action The toggle-link action used in the iconic Winchester Model 1873 rifle, one of the most famous lever-action firearms Picture showing a Volcanic Pistol A lever action is a type of action for repeating firearms that uses a manually operated cocki ...

, and

pump-action Pump action is a type of manual firearm action that is operated by moving a sliding handguard on the gun's forestock. When shooting, the sliding forend is pulled rearward to eject any expended cartridge (firearms), cartridge and typically to co ...

weapon designs.

Examples

M1 Garand The M1 Garand or M1 rifleOfficially designated as U.S. rifle, caliber .30, M1, later simply called Rifle, Caliber .30, M1, also called US Rifle, Cal. .30, M1 is a semi-automatic rifle that was the service rifle of the United States Army, U.S. ...

, gas-operated

semi-automatic rifle A semi-automatic rifle is a type of rifle that fires a single round each time the Trigger (firearms), trigger is pulled while automatically loading the next Cartridge (firearms), cartridge. These rifles were developed Pre-World War II, and w ...

M25 Sniper Weapon System The M25 sniper weapon system is a joint venture precision rifle built for the U.S. Army Special Forces and later adopted by the U.S. Navy SEALs. It was originally developed by the 10th Special Forces Group, based at Fort Devens, Mass., to fulfi ...

, gas operated, air cooled *

, bolt-action rifle *

, a straight-pull rifle *

, a gas-operated

rifle A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...

, a gas-operated

* Oerlikon KBA 25mm, gas-operated autocannon *

Imbel IA2 The IMBEL IA2 is a family of assault rifles and battle rifles, designed and manufactured in Brazil by IMBEL. It is designed to replace the FN FAL, FAL, M16 rifle, M16A2 and HK33 currently in service with the Brazilian Armed Forces. History ...

, a gas-operated

assault rifle An assault rifle is a select fire rifle that uses an intermediate cartridge, intermediate-rifle cartridge and a Magazine (firearms), detachable magazine.C. Taylor, ''The Fighting Rifle: A Complete Study of the Rifle in Combat'', F.A. Moyer '' ...

* IWI Tavor TAR-21, a gas-operated

Ruger Mini-14 The Mini-14 is a lightweight semi-automatic rifle manufactured by Sturm, Ruger & Co. Introduced in 1973, the design was outwardly similar to the M14 rifle and is, in appearance, a scaled-down version chambered in 5.56×45mm NATO, though with its ...

, a gas-operated

IMI Desert Eagle The Desert Eagle is a single-action, gas-operated, semi-automatic pistol capable of chambering the .50 Action Express, the largest centerfire cartridge of any magazine-fed, self-loading pistol and a number of other large calibers. Magnum Rese ...

, one of the few

handgun A handgun is a firearm designed to be usable with only one hand. It is distinguished from a long gun, long barreled gun (i.e., carbine, rifle, shotgun, submachine gun, or machine gun) which typically is intended to be held by both hands and br ...

s with such mechanism. *

Remington Model 8 The Remington Model 8 is a semi-automatic rifle designed by John Browning and produced by Remington Arms, introduced as the ''Remington Autoloading Rifle'' in 1905, though the name was changed to the ''Remington Model 8'' in 1911. History On Octo ...

, a recoil-operated rifle *

Chauchat The Chauchat ("show-sha", ) was the standard light machine gun or "machine rifle" of the French Army during World War I (1914–18). Its official designation was "Fusil Mitrailleur Modele 1915 CSRG" ("Machine Rifle Model 1915 CSRG"). Beginning ...

, a recoil-operated light machine gun * Remington Model 7600, a pump-action rifle * The Winchester model 1200, 1300,and Super-X (SXP) Pump Shotguns *

SIG-Sauer MPX The SIG MPX is a gas-operated submachine gun designed and manufactured by SIG Sauer, and is primarily chambered in 9×19mm Parabellum. It is a gas-operated firearm featuring a closed, rotating bolt. These design features, rare in submachine guns ...

, a gas-operated

submachine gun A submachine gun (SMG) is a magazine (firearms), magazine-fed automatic firearm, automatic carbine designed to fire handgun cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun, to descri ...

CMMG MkG The CMMG MkG is a .45 ACP carbine developed by CMMG. The weapon is an M16 derivative and uses a radial delayed blowback Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is ...

, the first AR15 derivative to use radial delayed blowback operation. *

Browning BLR The Browning BLR is a lever-action rifle manufactured for Browning Arms Company by Miroku Firearms in Japan. It comes in many different variations and is chambered in numerous calibers from small and fast ( .22-250 Remington and .243 Winchester ...

, a

lever action The toggle-link action used in the iconic Winchester Model 1873 rifle, one of the most famous lever-action firearms Picture showing a Volcanic Pistol A lever action is a type of action for repeating firearms that uses a manually operated coc ...

rifle with a rotating bolt *

L85A2 The SA80 (Small Arms for the 1980s) is a British family of 5.56×45mm NATO service weapons used by the British Army. The L85 Rifle variant has been the standard issue service rifle of the British Armed Forces since 1987, replacing the L1A1 Se ...

, A variant of the L85A1 *

S&T Motiv K16 S&T Motiv K16, formerly known as S&T Motiv K12, is a 7.62×51mm NATO general-purpose machine gun manufactured by S&T Motiv to replace the M60 machine gun for the Republic of Korea Armed Forces. The XK12 was first shown to the public in 2009, duri ...

, a gas-operated

general purpose machine gun A general-purpose machine gun (GPMG) is an air-cooled, usually belt-fed machine gun that can be adapted flexibly to various tactical roles for light and medium machine guns. A GPMG typically features a quick-change barrel design calibered for ...

References

External links

{{commons category, Rotating bolt
Computer Animation demonstrating rotating bolt in the M16Primer actuated M16 using rotating bolt
Firearm components Firearm actions