Rotating bolt
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Rotating bolt is a method of locking the breech (or rear barrel) of a firearm closed for firing. Johann Nicolaus von Dreyse developed the first rotating bolt firearm, the "Dreyse needle gun", in 1836. The Dreyse locked using the bolt handle rather than lugs on the bolt head like the Mauser M 98 or M16. The first rotating bolt rifle with two lugs on the bolt head was the Lebel Model 1886 rifle. The concept has been implemented on most firearms chambered for high-powered cartridges since the 20th century.
Design
breech
, rotates and locks into place, the lugs on the bolt locking into the breech or barrel extension.
Upon closing, the bolt goes forward into
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
pump-action
weapon designs. In some forms of delayed blowback, the rotating bolt is used as the delay mechanism: the bolt head rotates as the firing pin strikes, locking the chamber until the gas pressure reaches a safe level to extract. As the firing pin retracts, the bolt head turns anti-clockwise unlocking the breech.
Examples
- M1 Garand, gas-operated semi-automatic rifle[1]
- M25 Sniper Weapon System, semi-automatic rifle, gas operated, air cooled
- Lebel Model 1886 rifle, bolt-action rifle
- Steyr-Mannlicher M1895, a straight-pull rifle
- M16, a gas-operated rifle
- AK-47, a gas-operated rifle[2]
- Oerlikon KBA 25mm, gas-operated autocannon[3]
- Imbel IA2, a gas-operated assault rifle
- IWI Tavor TAR-21, a gas-operated assault rifle[4]
- Ruger Mini-14, a gas-operated semi-automatic rifle[5]
- IMI Desert Eagle, one of the few handgunswith such mechanism.
- Remington Model 8, a recoil-operated rifle
- Chauchat, 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, a gas-operated submachine gun[6]
- CMMG Mk 45 Guard, the first AR15 derivative to use radial delayed blowback operation.
- Browning BLR, a lever action rifle with a rotating bolt
- L85A2, A variant of the L85A1
See also
References
- ISBN 978-0-89689-241-5.
- ISBN 978-1440213762.
- ^ "Automatisch kanon Oerlikon KBA". Nationaal Militair Museum (in Dutch). Retrieved 2024-03-20.
- ^ Modern Firearms – TAR-21 assault rifle Archived 2004-10-12 at the Wayback Machine. World.guns.ru. Retrieved on 2024-03-21.
- ISBN 978-0-87341-824-9.
- ISBN 978-1-4402-3920-5.
External links
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