Pump-action
Encyclopedia
A pump-action rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

 or shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

 is one in which the handgrip can be pumped back and forth in order to eject a spent round of ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...

 and to chamber
Chamber (weaponry)
In firearms, the chamber is that portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired. Rifles and pistols generally have a single chamber in their barrels, while revolvers have multiple chambers in their cylinders and no chamber in their barrel...

 a fresh one. It is much faster than a bolt-action and somewhat faster than a lever-action
Lever-action
Lever-action is a type of firearm action which uses a lever located around the trigger guard area, to load fresh cartridges into the chamber of the barrel when the lever is worked. Most lever-action firearms are rifles, but lever-action shotguns and a few pistols have also been made...

, as it does not require the trigger hand to be removed from the trigger whilst reloading. When used in rifles, this action is also commonly called a slide action.

The term pump-action can also be applied to various airsoft
Airsoft
Airsoft is a sport in which participants shoot round non-metallic pellets launched via replica firearms.Gameplay varies in style and composition but often range from short-term skirmishes, organized scenarios, military simulations, historical reenactments, to competition target shooting events...

 guns and air gun
Air gun
An air gun is a rifle , pistol , or shotgun that fires projectiles by means of compressed air or other gas, in contrast to a firearm, which burns a propellant. Most air guns use metallic projectiles as ammunition. Air guns that only use plastic projectiles are classified as airsoft...

s, which use a similar mechanism to both load a pellet and compress a spring piston for power, or pneumatic guns where a pump is used to compress the air used for power. See the airgun article for information on how spring piston and pneumatic airguns work.

Advantages

The cycling time of a pump-action is quite short, often less than that of some semi-automatic
Semi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...

 designs. The manual operation gives a pump-action the ability to cycle rounds of widely varying power that a gas or recoil operated
Recoil operation
Recoil operation is an operating mechanism used in locked-breech, autoloading firearms. As the name implies, these actions use the force of recoil to provide energy to cycle the action...

 firearm would fail to cycle, such as most less-than-lethal rounds. The simplicity of the pump-action relative to a semi-automatic design also leads to improved durability and lower cost. It has also been noticed that the time taken to work the action allows the operator to identify and aim on a new target, avoiding a "spray and pray" usage.

An advantage of the pump-action over the bolt-action is its ease of use by both left- and right-handed
Handedness
Handedness is a human attribute defined by unequal distribution of fine motor skills between the left and right hands. An individual who is more dexterous with the right hand is called right-handed and one who is more skilled with the left is said to be left-handed...

 users: like lever-actions, pump-actions are frequently recommended as ambidextrous in sporting guidebooks.

Disadvantages

Like most lever-action rifles, most pump action shotguns and rifles do not use a detachable magazine. This makes for slow reloading, as the cartridges
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

 have to be inserted individually into the firearm. Some pump action shotguns and rifles, such as the Zlatoust RB-12
Zlatoust RB-12
The RB-12 Bandaevskogo is a shotgun of Russian origin. The weapon is not automatic and comes with a folding stock. The gun is designed by Alexander G. Bandaevskiy, chief designer and president of JSC Uralmashproekt....

, Italian Valtro PM5 and the American Remington 7600 series utilize detachable box magazines.

Layout

A pump-action firearm is typically fed from a tubular magazine underneath the barrel, which also serves as a guide to the movable forend. The rounds are fed in one by one through a port in the receiver, where they are pushed forward. A latch at the rear of the magazine holds the rounds in place in the magazine until they are needed. If it is desired to load the gun fully, a round may be loaded through the ejection port directly into the chamber, or cycled from the magazine, which is then topped off with another round. Pump shotguns with detachable box magazines or even drums exist, and may or may not allow the magazine to be inserted without stripping the top round.

Operating cycle

Nearly all pump-actions use a back-and-forward motion of the forend to cycle the action. The forend is connected to the bolt by one or two bars; two bars are considered more reliable because it provides symmetric forces on the bolt and pump and reduces the chances of binding. The motion of the bolt back and forth in a tubular magazine model will also operate the elevator, which lifts the shells from the level of the magazine to the level of the barrel.

After firing a round, the bolt is unlocked and the forend is free to move. The shooter pulls back on the forend to begin the operating cycle. The bolt unlocks and begins to move to the rear, which extracts and ejects the empty shell from the chamber, cocks the hammer, and begins to load the new shell. In a tubular magazine design, as the bolt moves rearwards, a single shell is released from the magazine, and is pushed backwards to come to rest on the elevator.

As the forend reaches the rear and begins to move forward, the elevator lifts up the shell, lining it up with the barrel. As the bolt moves forward, the round slides into the chamber, and the final portion of the forend's travel locks the bolt into position. A pull of the trigger will fire the next round, where the cycle begins again.

Most pump-action firearms do not have any positive indication that they are out of ammunition, so it is possible to complete a cycle and have an empty chamber. The risk of running out of ammunition unexpectedly can be minimized in a tubular magazine firearm by topping off the magazine by loading new rounds to replace the rounds that have just been fired. This is especially important when hunting, as many locations have legal limits on the magazine capacity: for example, three rounds for shotguns and five rounds for rifles.

The BSA Machine Carbine
BSA experimental model 1949
The BSA experimental model 1949 was a submachine gun of British origin intended to replace the Sten gun. The weapon was fed from a 34 side inserted box magazine and had an unusual pump-action bakelite covered handguard....

 used a unique pump-action that also required twisting the handguard.

Trigger disconnectors

Modern pump shotgun designs, such as the Remington 870
Remington 870
The Remington Model 870 is a U.S.-made pump-action shotgun manufactured by Remington Arms Company, Inc. It is widely used by the public for sport shooting, hunting, and self-defense. It is also commonly used by law enforcement and military organizations worldwide.-Development:The Remington 870 was...

 and Mossberg 500
Mossberg 500
Mossberg 500 is a series of shotguns manufactured by O.F. Mossberg & Sons. The 500 series comprises widely varying models of hammerless, pump action repeaters, all of which share the same basic receiver and action, but differ in bore size, barrel length, choke options, magazine capacity, and...

, have a safety feature called a trigger disconnector, which disconnects the trigger from the sear
Sear (firearm)
In a firearm, the sear is the part of the trigger mechanism which holds the hammer or striker back until the correct amount of pressure has been applied to the trigger; at which point the hammer or striker is released to discharge the weapon...

 as the bolt moves back, so that the trigger must be released and pulled again to fire the shotgun after it closes. Many early pump shotguns, such as the Winchester 1897, did not have trigger disconnectors, and would, if the trigger were held back, fire immediately upon closing. Some shooters feel this allows a higher rate of fire, and prefer models without this feature, such as the Ithaca 37
Ithaca 37
The Ithaca 37 is a pump-action shotgun made in large numbers for the civilian, military, and police markets. It utilizes a novel combination ejection/loading port on the bottom of the gun which leaves the sides closed to the elements. In addition, the outline of the gun is clean...

 and Winchester Model 12.
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