Tilting bolt

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M1895 Lee Navy with an open bolt, demonstrating its vertical locking surface on its bottom in front of the handle Rifle Lee Navy 95.jpg
M1895 Lee Navy with an open bolt, demonstrating its vertical locking surface on its bottom in front of the handle

Tilting bolt action is a type of locking mechanism often used in self-loading firearms and, rarely, in straight-pull repeating rifles. Essentially, the design consists of a moving bolt driven by some mechanism, most often a piston with gas pressure from the gas port behind the muzzle. The bolt drops down into receiver recess and locks on bolt closing. Tilting the bolt up and down locks-unlocks in the breech. This tilting allows gas pressure in the barrel from firing the gun to lower to safe levels before the cartridge case is ejected.


For handgun design, the tilting barrel as used in the Browning, is a similar operating mechanism. The tilting bolt has lost favor in contemporary firearm design of rifle caliber to locking systems such as the rotating bolt due to reasons such as increased wearing of the surfaces acted on, higher demands on the receiver due to transfer of locking stresses to it (e. g., it can't be made from aluminium or stamped sheet steel) & better potential accuracy of rotating bolt. Yet it is widespread in vintage firearms listed below. [1] [2] [3] [4]


See also

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  1. "How a Tilting Bolt Works - YouTube". M.youtube.com. 2010-11-04. Retrieved 2018-04-15.
  2. "L1A1 converts to full auto.wmv - YouTube". M.youtube.com. 2011-02-20. Retrieved 2018-04-15.
  3. Nathaniel F (2016-06-22). "Operating Systems 201: Tilting Bolt Locking - The Firearm BlogThe Firearm Blog". Thefirearmblog.com. Retrieved 2018-04-15.
  4. US 3112675,Colby, Richard H.,"Locking system for tilting firearm bolt",published 1963-12-03, assigned to The Secretary of the Army of The United States of America