View source for Action (firearms)

{{Short description|Functional mechanism of breech-loading}}
[[Image:ShotgunAction.JPG|thumb|A view of the [[break-action]] of a typical double-barreled shotgun, with the action open and the extractor visible. The opening lever and the safety catch are clearly visible.]]

In [[firearms]] terminology, an '''action''' is the functional mechanism of a [[breechloader|breechloading]] firearm that handles (loads, locks, fires, extracts, and ejects) the [[ammunition]] [[cartridge (firearms)|cartridge]]s, or the method by which that mechanism works.<ref>{{cite book |last=Brown |first=Edmund G. |author-link =Jerry Brown |title =Handgun Safety Certificate |publisher =[[California Department of Justice]] |date =2009 |location =[[West Sacramento, California]] |page =52 }}</ref> Actions are technically not present on [[muzzleloader]]s, as all those are [[single-shot]] firearms with a closed off breech with the powder and projectile manually loaded from the [[muzzle (firearms)|muzzle]]. Instead, the muzzleloader ignition mechanism is referred to as the ''lock'' (e.g. [[matchlock]], [[wheellock]], [[flintlock]], and [[caplock]]).

Actions can be categorized in several ways, including [[trigger (firearms)#Single-action|single action]] versus [[trigger (firearms)#Double-action only|double action]], [[break-action|break action]] versus [[lever-action]], [[pump-action]], [[bolt-action]], among many other types. The term action can also include short, long, and magnum if it is in reference to the  length of the rifle's receiver and the length of the bolt. The short action rifle usually can accommodate a cartridge length of {{convert|2.8|in|mm|abbr=on|lk=in}} or smaller. The long action rifle can accommodate a cartridge of {{convert|3.34|in|mm|abbr=on|lk=in}}, and the magnum action rifle can accommodate cartridges of {{convert|3.6|in|mm|abbr=on|lk=in}}.<ref>{{cite web|url=http://www.nssfblog.com/firstshotsnews/shooting-vocabulary-long-action-bolt-rifles-versus-short-action-bolt-rifles/|title=Shooting Vocabulary: Long-Action Bolt Rifles versus Short-Action Bolt Rifles|website=www.nssfblog.com|access-date=2017-04-07|archive-date=2017-04-07|archive-url=https://web.archive.org/web/20170407145903/http://www.nssfblog.com/firstshotsnews/shooting-vocabulary-long-action-bolt-rifles-versus-short-action-bolt-rifles/|url-status=live}}</ref>

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== Single-shot actions ==
{{main|Single-shot}}
Single-shot actions operate only to ignite a [[cartridge (firearms)|cartridge]] that is separately set up ("in battery") for firing, and are incapable of moving the cartridge, itself. As the name implies, all single-shot firearms (unless they are [[multiple-barrel firearm|multi-barreled]]) can only hold one round of [[ammunition]] and need to be manually reloaded after every firing. Historically, these are the earliest cartridge firearm actions invented.

===Breechblock===
{{main|Breechblock}}
[[File:Firearm actions.svg|thumb|400px|right|Diagram of various "block" firearm actions]]

====Dropping block====
The '''dropping block''' are actions wherein the [[breechblock]] lowers or "drops" into the [[Receiver (firearms)|receiver]] to open the breech, usually actuated by an underlever. There are two principal types of dropping block: the tilting block and the falling block.

====Pivoting block====
In a '''tilting block''' or '''pivoting block''' action, the breechblock is hinged on a pin mounted at the rear (in contrast with [[tilting bolt]], which is not hinged). When the lever is operated, the block tilts down and forward, exposing the chamber. The best-known pivoting block designs are the [[Peabody action|Peabody]], the Peabody–Martini, and [[Ballard Rifle|Ballard]] actions.

The original Peabody rifles, manufactured by the [[Providence Tool Company]], used a manually cocked side-hammer. Swiss gunsmith Friedrich Martini developed a pivoting block action by modifying the Peabody, which incorporated a hammerless striker that was cocked by the operating lever with the same single efficient motion that also pivoted the block. The 1871 [[Martini–Henry]] which replaced the "trapdoor" [[Snider–Enfield]] was the standard British Army rifle of the later Victorian era, and the Martini is also a popular action for civilian rifles.

Charles H. Ballard's self-cocking tilting-block action was produced by the [[Marlin Firearms Company]] from 1875 and earned a superlative reputation among long-range "Creedmoor" target shooters. Surviving Marlin Ballards are today highly prized by collectors, especially those mounted in the elaborate Swiss-style Schützen stocks of the day.

====Falling block====
{{Main|Falling-block action}}
[[Image:Ruger no1 243 left open.jpg|thumb|right|250px|Ruger No. 1 single-shot falling-block rifle with action open]]
In a '''falling block''' or '''sliding block''' action, a solid metal breechblock "slides" vertically in grooves cut into the breech of the firearm and actuated by a lever. Examples of firearms using the falling-block action are the [[Sharps rifle]] and [[Ruger No. 1]].

====Rolling block====
{{Main|Rolling block}}
In a '''rolling block''' action, the breechblock takes the form of a part-cylinder, with a pivot pin through its axis. The operator rotates or "rolls" the block to open and close the breech; it is a simple, rugged, and reliable design. Rolling blocks are most often associated with firearms made by [[E. Remington and Sons|Remington]] in the late 19th century; in the Remington action the hammer serves to lock the breech closed at the moment of firing, and the block in turn prevents the hammer from falling with the breech open.

====Hinged block====
The '''hinged block''' used in the earliest metallic-cartridge breechloaders designed for general military issue began as conversions of muzzle-loading [[rifle-musket]]s. The upper rear portion of the barrel was filed or milled away and replaced by a hinged breechblock, which opened upward to permit loading. An internal angled firing pin allowed the re-use of the rifle's existing side-hammer. The Allin action made by Springfield Arsenal in the US hinged forward; the [[Snider–Enfield]] used by the British opened to the side. Whereas the British quickly replaced the Snider with a dropping-block [[Peabody action|Peabody-style]] Martini action, the US Army felt the trapdoor action to be adequate and followed its muzzleloader conversions with the new-production [[Springfield Model 1873]], which was the principal longarm used as a weapon in the [[American Indian Wars|Indian Wars]] and was still in service with some units in the [[Spanish–American War]].

===Break-action===
{{Main|Break action}}
A '''break action''' is a type of firearm where the barrel(s) are hinged and can be "broken open" to expose the breech. Multi-barrel break action firearms are usually subdivided into over-and-under or side-by-side configurations for two barrel configurations or "[[combination gun]]" when mixed rifle and shotgun barrels are used.

===Bolt-action===
{{Main|Bolt action}}
<!-- Mechanism of a single-shot bolt-action is to be added -->Although bolt-action guns are usually associated with fixed or detachable box magazines (multi-shot), some are single-shot. In fact, the first general-issue military breechloader was a single-shot bolt action: the paper-cartridge [[Prussian needle gun]] of 1841. France countered in 1866 with its superior [[Chassepot rifle]], also a paper-cartridge bolt action. The first metallic-cartridge bolt actions in general military service were the [[Berdan rifle|Berdan Type II]] introduced by Russia in 1870, the [[Mauser Model 1871]], and a modified Chassepot, the [[Gras rifle]] of 1874; all these were single-shots.

Today, most top-level smallbore match rifles are single-shot bolt action rifles.

Single-shot bolt actions in .22 caliber were also widely manufactured as inexpensive "boys' guns" in the earlier 20th century; and there have been a few single-shot bolt-action shotguns, usually in .410 bore.

===Eccentric screw action===
The '''eccentric screw''' action first seen on the [[M1867 Werndl–Holub]] and later on the [[Magnum Research]] Lone Eagle pistol, the breech closure is a rotating drum with the same axis, but offset from the bore. When locked, a firing pin aligns with the [[Primer (firearms)|primer]], the breech is otherwise solid.  When rotated open, a slot in the drum is exposed for extraction and feeding of a new round. Though first used on the Werndl-Holub, this action is commonly known as a cannon breech due to its association with the French 75mm Model of 1897 cannon.  The French M1897 was, itself, based on William Hubbell's {{US Patent|149478}}.

===Other actions===
*'''The [[Ferguson rifle]]''': British Major Patrick Ferguson designed his rifle, considered to be the first military [[breechloader]] in the 1770s. A plug-shaped breechblock was screw-threaded so that rotating the handle underneath would lower and raise it for loading with ball and loose powder; the flintlock action still required conventional priming.
*'''The [[M1819 Hall rifle|Hall rifle]]''': First U.S. cavalry breechloader, originally made in flint but later made-in and converted to percussion in 1830s–1840s. The breech section tilts up to accept a paper cartridge. Excellent machine-made construction, but still tended to leak gas at the breech.
*'''The [[Kammerlader]]''': A crank-operated Norwegian firearm produced around the time of the Prussian Needle-gun. Originally used a paper cartridge. Later, many were converted to rimfire; this was the first Norwegian breechloader.
*'''The [[Tarpley carbine]]''': This is categorized into falling block action, but the breech block is hinged, unlike the others.
*'''The [[Morse Carbine]]''': This mostly brass action is somewhat like the [[Hall rifle]], except it was designed to take a special centerfire cartridge. Very few of these were actually made; all were constructed in the late 1850s.
*'''The [[Joslyn rifle]]''':
*'''[[Rising Breech Carbine]]''':

==Repeating actions==
{{main|Repeating firearm}}
Repeating actions are characterized by [[reciprocating motion|reciprocating]]/[[rotating]] components that can move [[cartridge (firearms)|cartridge]]s in and out of battery from an [[ammunition]]-holding device (which is a [[magazine (firearms)|magazine]], [[cylinder (firearms)|cylinder]], or [[ammunition belt|belt]]), which allows the gun to hold multiple rounds and shoot repeatedly before needing a manual ammunition reload.

===Manual operation===
====Revolver====
{{Main|Revolver}}
[[File:M&Prevolver.jpg|thumb|250px|Smith & Wesson M&P revolver]]
A '''revolver''' is a multi-[[chamber (firearms)|chamber]] (but single-[[gun barrel|barrel]]led) firearm that houses cartridges in a rotary [[cylinder (firearms)|cylinder]] which [[indexing (motion)|index]]es each round into alignment with the [[gun barrel#Bore|bore]] (with the help of a forcing cone) prior to each shot.  Revolvers are most often [[handgun]]s;<ref>{{cite web|url=http://www.samuelcolt.net/colt-revolver-history/revolver-history/|title=Revolver History – Colt Revolver|website=www.samuelcolt.net|access-date=2016-07-15|archive-date=2016-09-18|archive-url=https://web.archive.org/web/20160918075330/http://www.samuelcolt.net/colt-revolver-history/revolver-history/|url-status=live}}</ref> however, examples of [[revolving rifle]]s, shotguns, and cannons have been made.  The cylinder is most often rotated via [[linkage (mechanical)|linkage]] to a manually manipulated external [[hammer (firearms)|hammer]], although some revolvers are "double-action" and can use the manual pull of the [[trigger (firearms)|trigger]] to drive both the cylinder rotation and hammer cocking. Some examples of firearms using the revolver principle are the [[Smith & Wesson Model 3]] and [[Colt M1889|Colt Model 1889]].

====Bolt action====
{{Main|Bolt action}}
[[File:Open bolt action.jpg|thumb|right|250px|Barreled action for bolt-action rifle]]
In '''bolt-action''' firearms, the opening and closing of the breech is operated by direct manual manipulation of the [[bolt (firearms)|bolt]] via a protruding [[cocking handle|bolt handle]].

===== Rotating bolt action =====
Most bolt-actions utilize a rotating bolt ("turn-pull") design, where the bolt handle must be rotated upwards for unlocking before the bolt can be pulled back to opening the breech and eject any spent cartridge, and must be rotated back down for locking after the bolt closes the breech. The three predominant rotating bolt-action systems are the [[Gewehr 98#M98 controlled-feed bolt-action system|Mauser]], [[Lee–Enfield]], and [[Mosin–Nagant]] systems, with the Mauser system emerging into the mainstream as the most widely used rotating bolt-action design.

===== Straight-pull action =====
There are also straight pull bolt-action systems that use complex bolt head designs to facilitate locking instead of needing to rotate the bolt handle every time.[[File:M1895 US Navy Straight Pull Rifle.jpg|thumb|250px|U.S. [[M1895 Lee Navy]] straight-pull rifle]]
In the Mauser-style [[bolt action#Rotating bolt|turn-bolt]] action,<ref>{{cite web|url=https://www.youtube.com/watch?v=GhABWdIx8bk| archive-url=https://ghostarchive.org/varchive/youtube/20211114/GhABWdIx8bk| archive-date=2021-11-14 | url-status=live|title=Best Straight Pull Rifle Actions – Blaser, Merkel Helix, Heym, Browning Acera|last=USOG|date=27 November 2016|via=YouTube}}{{cbignore}}</ref><ref>{{cite web|url=https://www.youtube.com/watch?v=spJQapFXEO8| archive-url=https://ghostarchive.org/varchive/youtube/20211114/spJQapFXEO8| archive-date=2021-11-14 | url-status=live|title=Straight-Pull Rifle Test|last=Fieldsports Channel|date=7 December 2016|via=YouTube}}{{cbignore}}</ref> the [[cocking handle|bolt handle]] must be rotated upward, pull rearward, pushed forward, and finally rotated back downward into lock.  In a straight pull bolt-action, the bolt can be cycled without rotating, hence reducing the required range of motion by the shooter from four movements to two, with the goal of increasing the [[rate of fire]].  The [[Ross rifle|Ross]] and [[Schmidt–Rubin]] rifles load via [[stripper clip]]s, albeit of an unusual [[paperboard]] and steel design in the Schmidt–Rubin rifle, while the Mannlicher uses [[Clip (ammunition)#En bloc|en-bloc clip]]s.  The Schmidt–Rubin series, which culminated in the [[K31]], are also known for being among the most accurate military [[service rifle]]s ever made.  Yet another variant of the straight pull bolt-action, of which the [[M1895 Lee Navy]] is an example, is a camming action in which pulling the bolt handle causes the bolt to rock, freeing a stud from the receiver and unlocking the bolt.

In 1993, the German firearms 
company [[Blaser]], introduced the [[Blaser R93]], a new straight pull bolt-action rifle where locking is achieved by a series of concentric "claws" that protrude/retract from the bolthead, a design that is referred to as ''Radialbundverschluss'' ("radial connection"). As of 2017 the Rifle Shooter magazine<ref>{{Cite web |date=2022-06-15 |title=Straight pull rifles - in depth analysis of three popular straight pulls |url=https://gundog-journal.com/article/straight-pull-rifles-in-depth-analysis-of-three-popular-straight-pulls |access-date=2023-05-15 |website=Rifle Shooter |language=en}}</ref> listed its successor [[Blaser R8]] as one of the three most popular straight pull bolt-action together with [[Merkel (firearms manufacturer)|Merkel]] Helix<ref>{{Cite web |url=http://www.sporting-rifle.com/reviews/merkel-rx-helix-review/ |title=Merkel RX Helix Review {{!}} Sporting Rifle magazine |access-date=2020-10-30 |archive-date=2020-11-08 |archive-url=https://web.archive.org/web/20201108045609/https://www.sporting-rifle.com/reviews/merkel-rx-helix-review/ |url-status=live }}</ref> and [[Browning Arms Company|Browning]] Maral.<ref>{{Cite web |url=https://www.gunmart.net/gun-reviews/firearms/rifles/browning_maral |title=Browning Maral {{!}} Straight-Pull Rifles Reviews {{!}} Gun Mart |access-date=2020-10-30 |archive-date=2020-11-06 |archive-url=https://web.archive.org/web/20201106072021/https://www.gunmart.net/gun-reviews/firearms/rifles/browning_maral |url-status=live }}</ref> Some other notable modern straight pull bolt-action rifles are made by [[Chapuis Armes|Chapuis]],<ref>{{Cite web |url=https://www.thefirearmblog.com/blog/2017/04/11/chapuis-armes-rols-new-straight-pull-bolt-action-rifle/ |title=Chapuis Armes "ROLS": New Straight Pull Bolt Action Rifle – The Firearm BlogThe Firearm Blog |access-date=2020-10-30 |archive-date=2020-11-02 |archive-url=https://web.archive.org/web/20201102180234/https://www.thefirearmblog.com/blog/2017/04/11/chapuis-armes-rols-new-straight-pull-bolt-action-rifle/ |url-status=live }}</ref> [[Heym (gun manufacturer)|Heym]],<ref>{{Cite web |url=https://www.shootinguk.co.uk/reviews/rifle/heym-sr30-straight-pull-rifle-review |title=Heym SR30 straight-pull rifle review review – Shooting UK |access-date=2020-10-30 |archive-date=2020-11-01 |archive-url=https://web.archive.org/web/20201101233039/https://www.shootinguk.co.uk/reviews/rifle/heym-sr30-straight-pull-rifle-review |url-status=live }}</ref> [[Lynx Rifles|Lynx]],<ref>{{Cite web |url=http://www.sporting-rifle.com/reviews/lynx-94-review/ |title=Lynx 94 Review {{!}} Sporting Rifle magazine |access-date=2020-10-30 |archive-date=2020-10-26 |archive-url=https://web.archive.org/web/20201026135251/https://www.sporting-rifle.com/reviews/lynx-94-review/ |url-status=live }}</ref> [[Rößler (firearms manufacturer)|Rößler]],<ref>{{Cite web |url=https://www.shootinguk.co.uk/reviews/rifle/titan-16-straight-pull-rifle |title=Titan 16 straight-pull rifle review – Shooting UK |access-date=2020-10-30 |archive-date=2020-11-02 |archive-url=https://web.archive.org/web/20201102024329/https://www.shootinguk.co.uk/reviews/rifle/titan-16-straight-pull-rifle |url-status=live }}</ref> Strasser,<ref>{{Cite web |url=https://www.shootinguk.co.uk/reviews/shotgun/strasser-rs-solo |title=Strasser RS Solo review – Shooting UK |access-date=2020-10-30 |archive-date=2020-11-02 |archive-url=https://web.archive.org/web/20201102150455/https://www.shootinguk.co.uk/reviews/shotgun/strasser-rs-solo |url-status=live }}</ref> and Steel Action.<ref>{{Cite web |url=https://www.thefirearmblog.com/blog/2017/06/07/german-straight-pull-bolt-action-rifles-steel-action/ |title=German Straight Pull Bolt Action Rifles by Steel Action – The Firearm BlogThe Firearm Blog |access-date=2020-10-30 |archive-date=2021-10-30 |archive-url=https://web.archive.org/web/20211030175810/https://www.thefirearmblog.com/blog/2017/06/07/german-straight-pull-bolt-action-rifles-steel-action/ |url-status=live }}</ref>

In the sport of [[biathlon]], because shooting speed is an important performance factor and semi-automatic guns are illegal for race use, straight pull bolt-actions are quite common, and are used almost exclusively on the [[Biathlon World Cup]]. The first company to make straight pull bolt-actions for [[.22 caliber]] was [[J. G. Anschütz]]; the action is specifically the straight-pull [[ball bearing]]-lock action, which features spring-loaded ball bearings on the side of the bolt which lock into a groove inside the bolt's housing. With the new design came a new dry-fire method; instead of the bolt being turned up slightly, the action is locked back to catch the firing pin.

====Pump-action====
{{Main|Pump-action}}
[[File:Winchester 1897.jpg|thumb|250px|A [[Winchester M1897]], one of the first successful pump-action shotgun designs]]
In '''pump-action''' firearms, a sliding grip at the fore-end beneath the barrel is manually operated by the user to eject and chamber cartridges. Pump actions are predominantly found in [[shotgun]]s.  Some examples of firearms using the pump-action are the [[Winchester Model 1912]], [[Remington 870]], and [[Mossberg 500]].

====Lever-action====
{{Main|Lever-action}}
The '''lever-action''' firearms, a [[mechanical linkage|linked]] lever is manually operated to eject and chamber cartridges. Some examples of firearms using lever-action are the [[Henry rifle|Henry Model 1860]], [[Winchester Model 1876]], and [[Marlin Model 1894]].

====Bolt release====
The '''bolt release''' or '''lever release''' action<ref>{{cite web|url=http://www.gunmart.net/gun-reviews/firearms/rifles/southern-gun-co-lr9|title=Southern Gun Co LR9|last=Gun Mart TV|date=15 December 2016|publisher=Aceville Magazines Ltd.|via=Gunmart.net|access-date=14 October 2017|archive-date=14 October 2017|archive-url=https://web.archive.org/web/20171014184255/http://www.gunmart.net/gun-reviews/firearms/rifles/southern-gun-co-lr9|url-status=live}}</ref> is a hybrid repeating action that uses the physical manipulation of a bolt release lever/button to complete the cartridge chambering process. However, unlike the lever action (which demands the shooter's hand to actually provide the force needed for cycling the action), bolt release firearms eject the used cartridge automatically without involving the lever, usually via [[Blowback (firearms)|blowback]] or [[gas operation]], and often uses a spring-assisted mechanism to chamber the next round. However, after moving rearwards the [[bolt (firearms)|bolt]] is stopped by a bolt catch and will not move back into battery position and chamber the new round, until the user manually disengages the catch by depressing a release lever/button.  Due to the fact that the action can not complete its loading cycle without manual input from the user, it is technically a manually operated action rather than a self-loading one.

Whilst the basic principle can be traced back to other self-ejecting rifles, such as the single-shot [[H&R Firearms|Harrington & Richardson]] Model 755 rifle, this action has since been popularized in the United Kingdom by Southern Gun Company, who manufacture with "Manually Actuated Release System" (MARS) action rifles/[[pistol-caliber carbine]]s in [[.223 Remington|.223]], [[.308 Winchester|.308]], [[9mm Parabellum|9mm]] and [[.45 ACP]] calibers,<ref>{{cite web|title=Southern Gun Company Example Gun Builds|url=http://www.southern-gun.co.uk/example-gun-build/#9mmlr|publisher=Southern Gun Company|access-date=14 October 2017|archive-date=2 October 2017|archive-url=https://web.archive.org/web/20171002212548/http://www.southern-gun.co.uk/example-gun-build#9mmlr|url-status=live}}</ref> as the interrupted mechanism complies with [[Firearms (Amendment) Act 1988|The Firearms (Amendment) Act 1988]] which bans possession of self-loading [[Centerfire ammunition|centrefire]] rifles.  The French company [[Verney-Carron]] makes and exports the ''Speedline'' hunting rifle and the ''Véloce'' shotgun, which has caused some [[moral panic|moral concern]] in the [[mainstream media]] in Australia due to lobbying by the [[Australian Greens|Greens]] and anti-gun groups such as [[Gun Control Australia]],<ref>{{cite web|url=https://www.abc.net.au/news/2018-05-30/push-to-import-rapid-fire-shotgun-to-australia-sparks-concerns/9807790|title=Push to import new 'rapid-fire' shotgun into Australia sparks concerns|last=Carbonell|first=Rachel|date=2018-05-30|work=ABC News|access-date=2020-06-01|archive-date=2020-10-24|archive-url=https://web.archive.org/web/20201024190519/https://www.abc.net.au/news/2018-05-30/push-to-import-rapid-fire-shotgun-to-australia-sparks-concerns/9807790|url-status=live}}</ref> with [[David Shoebridge]] quoting the term "semi-semi-automatic".<ref>{{cite web|url=https://davidshoebridge.org.au/2018/06/08/media-release-new-semi-semi-automatic-firearms-fresh-risk-to-public-safety/|title=New "semi-semi-automatic" firearms fresh risk to public safety|publisher=David Shoebridge – Media Release|date=2018-06-08|access-date=2020-06-01|archive-date=2020-10-29|archive-url=https://web.archive.org/web/20201029102529/https://davidshoebridge.org.au/2018/06/08/media-release-new-semi-semi-automatic-firearms-fresh-risk-to-public-safety/|url-status=dead}}</ref>  Similarly, [[Savage Arms]] has introduced the A17R and A22R rimfire rifles (both modified from its new A-series rifles, with a bolt release lever in front of the [[trigger guard]]), aiming at the Australian market, but law enforcement agencies such as the [[Northern Territory Police]] has attempted to unilaterally defining these rifles as "linear repeating firearms with assisted ejection" and reclassify them as [[semi-automatic rifle|semi-automatic]],<ref>{{cite web|url=https://www.katherinetimes.com.au/story/6515904/new-firearm-laws-catch-owners-by-surprise/|title=New firearm laws catch owners by surprise|last=McLennan|first=hris|date=2019-11-28|publisher=Katherine Times|access-date=2020-06-01|archive-date=2020-10-22|archive-url=https://web.archive.org/web/20201022010139/https://www.katherinetimes.com.au/story/6515904/new-firearm-laws-catch-owners-by-surprise/|url-status=live}}</ref> and hence prohibited without at least a Category C license, which is off-limit to most urban and rural residents who do not own farms.  In 2020, [[Česká zbrojovka firearms|CZ]] also introduced CZ 515, a bolt-release modified version of the CZ 512, to the Australian market via its importer [[Winchester Repeating Arms Company|Winchester Australia]].  The Turkish manufacturer Pardus Arms also produces the [[12-gauge shotgun|12 gauge]]-caliber BRS17 shotgun, which uses a bolt release button on the back of the [[receiver (firearm)|receiver]] to chamber rounds before firing.

====Other actions====
*'''[[Rotary cannon]]''': [[Gatling gun]], [[M134 Minigun]]
*'''[[Chain gun]]''': [[AAI In-Line]], [[M230 chain gun|Hughes Chain Gun]], [[Guycot chain rifle|Guycot Chain Rifle]], [[Treeby chain gun]]
*'''[[Kalthoff repeater]]'''
*'''[[Cookson repeater]]'''
*'''[[Belton flintlock]]'''
*'''[[The Jennings Magazine Rifle]]'''
*'''[[Meigs Sliding Guard Action Repeater]]'''
*'''[[Roper repeater]]'''
*'''[[The Orvill Robinson Model 2]] rifle:''' Orvill Robinson, a New York-based firearms designer, developed two rifles. His first, patented in 1870 and commonly referred to by collectors as the "Model 1" though it has no official designation, was a precursor to straight pull bolt-actions like the Mannlicher M1886. The second rifle designed by Robinson, patented in 1872, was very different, employing a double hinged action that folded upward from the receiver to remove the spent casing and back down and forward to chamber a new round. Though hammer-fired, it is recognizable as a manually actuated ancestor of the toggle action found in firearms such as the Luger Parabellum 1908 pistol or Pedersen Rifle.
*'''[[Krag–Petersson|Krag-Petersson Rifle]]''' Though frequently classified as only single-shot firearms, one tilting block rifle usually falls under the category of repeating firearms. The user, upon ejecting a round from the chamber, would load a round from the underbarrel magazine onto the loading surface of the tilting block, then raise it to the mouth of the chamber where the user could then easily push it forward into the chamber. Though this would not meet most standards of "repeating" for most modern users, the classification has been in use historically.
*'''Remington-Rider Magazine Pistol''' has a manually actuated rolling block action to pull a cartridge from a tubular magazine set below the barrel and simultaneously cock the firearm. The block was rolled back into battery, loading the cartridge into the chamber, by spring pressure while the hammer remained in the cocked position.
[[File:Nylon66.JPG|thumb|250px|Remington Nylon 66 .22 Rimfire semi-automatic rifle]]

===Autoloading operation===
[[File:Firearm operating systems Public Domain CC0 by Grasyl.svg|thumb|250px|Schematic of automatic firearm operations]]
====Blowback operation====
{{Main|Blowback (firearms)}}
[[File:FAMAS Bolt-gr.PNG|thumb|right|A schematic of the lever-delayed blowback mechanism used in the FAMAS assault rifle]]
The '''blowback operation''' is a system in which [[semi-automatic firearm|semi-automatic]] and [[fully automatic firearm]]s operate through the energy created by combustion in the chamber and bore acting directly on the bolt face through the cartridge. In blowback operation the bolt is not locked to the chamber, relying only on spring pressure and inertia from the weight of the bolt to keep the action from opening too quickly. Blowback operation is used for low-powered cartridges due to the weight of the bolt required.

Delayed blowback actions use some mechanism to slow down rearward travel of the bolt, allowing this action to handle more powerful ammunition and/or reduced weight of the bolt.

=====Examples of blowback operation=====
*'''Simple blowback''': [[Halcón M-1943]], [[Uzi submachine gun]], Varan PMX-80
*'''Advanced primer ignition''': [[Becker Type M2 20 mm cannon|Becker Type M2]], [[Oerlikon 20 mm cannon|Oerlikon 20 mm]], [[Mk 19 grenade launcher]], [[Atchisson AA-12]], [[Norinco LG5 / QLU-11|QLU-11 (LG5)]]
*'''Lever-delayed blowback''': [[FAMAS (rifle)|FAMAS]], [[Sterling 7.62]], [[AA-52]], 2B-A-40, [[TKB-517]]
*'''Radial-delayed blowback''': [[CMMG MkG]]
*'''Roller-delayed blowback''': [[SIG 510]], [[Heckler & Koch MP5|HK MP5]], [[Heckler & Koch P9|HK P9]], [[Heckler & Koch G3|HK G3]]
*'''Gas-delayed blowback''': [[Volkssturmgewehr 1-5]], [[Heckler & Koch P7|HK P7]], [[Steyr GB]]
*'''Primer-actuated unlocking''': Garand Model 1919, Postnikov APT, Springfield 1903 primer-actuated rifle and Clarke carbine
*'''Toggle-delayed blowback''': [[Schwarzlose MG M.07/12]], [[Luger rifle]] and [[Pedersen rifle]]
*'''Screw-delayed blowback''': [[Salvator-Dormus M1893]] & [[Demro TAC-1]] (Helical screw), Sheppard automatic rifle and [[Thompson Autorifle]] (Turnbolt)
*'''Blish Lock''': early [[Thompson submachine gun]]s
*'''Hesitation locked''': [[Remington Model 51]] and [[Remington R51|R51]] pistols, [[M50 Reising]], [[SIG MKMO]] and [[Armalite AR-18|Rudd Arms AR-180]]
*'''Flywheel-delayed blowback''': [[Barnitzke machine gun]], Kazachok SMG, and MGD PM-9 
*'''Detent-delayed blowback''': Show Low Manufacturing Black-Jack 
*'''Chamber-ring delayed blowback''': [[Seecamp]] pistol
*'''Pneumatic-delay''': [[Suomi KP/-31]] and Moore submachine gun

====Blow-forward operation====
{{Main|Blow forward}}
The '''blow-forward''' operation uses a fixed breech and moving barrel that is forced forward relative to the breech by the friction of the projectile against the bore as well as the breech recoiling away from the barrel.  The barrel is spring loaded and returns automatically to chamber a fresh round from the magazine.<ref>{{cite book |last=Cunningham |first=Grant |url= |title=Gun Digest Shooter's Guide to Handguns |publisher=Gun Digest Books |year=2012 |isbn=978-1-4402-3276-3 |location=Iola, Wisconsin |page=22}}</ref> Examples of this action are the [[Steyr Mannlicher M1894]], [[Hino Komuro M1908 Pistol]] and the [[Schwarzlose Model 1908]].

====Recoil operation====
{{Main|Recoil operation}}
The '''recoil operation''' is a type of [[locked-breech]] action used in semi-automatic and fully automatic firearms. It also uses energy from the combustion in the chamber acting directly on the bolt through the cartridge head, but in this case the firearm has a reciprocating barrel and breech assembly, combined with a bolt that locks to the breech. The breech remains locked as the bolt and barrel travel rearward together for some distance, allowing pressure in the chamber to drop to a safe level before the breech is opened.

=====Examples of recoil operation=====
*'''Short-recoil''': [[M1911 Colt pistol|Colt M1911]], [[MAB PA-15]], [[Browning Hi-Power]], [[Heckler & Koch USP|HK USP]], [[Glock pistol|Glock]], [[Mamba Pistol]], [[M2 Browning machine gun]], [[MG42]], [[Vz. 52 (pistol)|Vz 52 pistol]], Revol Arms DL45, [[M82 Barrett rifle|M82]]
*'''Long-recoil''': [[Browning Auto-5|Browning Auto 5]], [[Frommer Stop|Femaru STOP Pistol]], [[Mars Automatic Pistol]], [[Chauchat]]
*'''Inertia''': [[Sjögren shotgun|Sjögren Inertial]], certain [[Benelli (firearms)|Benelli shotguns]]

====Gas operation====
{{Main|Gas-operated reloading|Direct impingement}}
[[File:DIRECTM16.gif|thumb|250px|Direct impingement]]
[[File:Kinematik Gasdrucklader Rückdrucklader mit Kammereinleitung.svg|thumb|250px|Fluted chamber direct impingement]]
The '''gas operation''' is a system of operation mechanism used to provide energy to semi-automatic and fully automatic firearms. In gas-operation, a portion of high pressure gas from the cartridge being fired is tapped through a hole in the barrel and diverted to operate the action. There are three basic types: long stroke gas piston (where the gas piston goes the same distance as the operating stroke of the action parts, and is often attached to the action parts), short stroke gas piston (where the gas piston travels a shorter distance than the operating stroke of the action parts), and direct impingement (AKA "direct gas", "gas impingement", where there is no piston, and the gas acts directly on the action parts). A fourth type, now considered obsolete and ineffective, are those systems based on the Bang rifle that utilize a muzzle cap to capture gas after the bullet has left the barrel. While this system is successful in boosting the operating power of recoil operated guns, it is insufficient and too susceptible to fouling for use as the primary operating system.

=====Examples of gas operation=====
*'''Short-stroke gas piston''': [[FN FAL]], [[Sterling SAR-87|SAR-87]], [[Heckler & Koch G36|HK G36]]
*'''Long-stroke gas piston''': [[M1 Garand]], [[AK-47]], [[FN FNC]]
*'''[[Direct impingement]]''': [[MAS 49]], [[M16 rifle|M16]], [[AG-42]]
*'''[[Gas trap]]''': [[Gewehr 41]], [[Bang M1922 rifle]]<ref>{{cite web|url=https://www.nps.gov/spar/learn/historyculture/exper-semi-auto-rifles-1919-31.htm|title=Experimental semi-automatic rifles, 1919-1931- excluding Garand's and Pedersen's rifles – Springfield Armory National Historic Site (U.S. National Park Service)|website=www.nps.gov|access-date=2009-06-28|archive-date=2009-12-02|archive-url=https://web.archive.org/web/20091202235030/http://www.nps.gov/spar/historyculture/exper-semi-auto-rifles-1919-31.htm|url-status=live}}</ref>

==See also==
*[[Locked-breech]]
*[[Lock (firearm)]]
**[[Matchlock]]
**[[Wheellock]]
**[[Flintlock]]
**[[Caplock mechanism|Caplock]]
<!--  *[[Harmonica gun]] too far from article topic -->
*[[Trigger (firearms)|Trigger]]

==References==
{{Reflist}}

==External links==
* {{YouTube|id=GJzXG7MYX1c|title=How Small Arms Work – Training Movie}}
* [https://www.youtube.com/watch?v=qTlvw5XmiU4 How Does It Work: Toggle Actions] Forgotten Weapons

{{Firearms}}

{{DEFAULTSORT:Firearm Action}}
[[Category:Firearm actions| ]]
[[Category:Firearm terminology]]