
An automatic shotgun is an
automatic firearm
An automatic firearm or fully automatic firearm (to avoid confusion with semi-automatic firearms) is a self-loading firearm that continuously Chamber (firearms), chambers and fires Cartridge (firearms), rounds when the trigger (firearms), trigger ...
that fires
shotgun shell
A shotgun cartridge, shotshell, or shell is a type of rimmed, cylindrical (straight-walled) ammunition used specifically in shotguns. It is typically loaded with numerous small, spherical sub-projectiles called shot. Shotguns typically use a ...
s (thereby making it a
shotgun
A shotgun (also known as a scattergun, peppergun, or historically as a fowling piece) is a long gun, long-barreled firearm designed to shoot a straight-walled cartridge (firearms), cartridge known as a shotshell, which discharges numerous small ...
) and uses some of the energy of each shot to automatically cycle the action and load a new round. It will fire repeatedly until the trigger is released or ammunition runs out. Automatic shotguns have a very limited range, but provide tremendous firepower at close range.
Design
Automatic shotguns generally employ mechanisms very similar to other kinds of
automatic weapons. There are several methods of operation, with the most common being
gas
Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...
,
recoil
Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, for according to Newton's third law the force requ ...
, and
blowback operated:
*

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 ...
uses the pressure of the gas (created by the burning propellant) behind the projectile to unlock the bolt assembly and then move it rearward.
*
Blowback operation
Blowback is a system of operation for Semi-automatic firearm, 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 bl ...
uses the backward force applied by the projectile (due to
Newton's third law of motion
Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows:
# A body r ...
) to retract the bolt assembly.
*
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 ...
uses the backward force to retract the entire barrel and bolt assembly, which unlock at the rear of the barrel's path.
Each of these methods use springs to return the retracted parts to their forward positions and restart the cycle.
Many automatic shotguns are capable of
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 ...
, meaning they can fire in multiple modes (
semi-automatic,
burst
Burst may refer to:
*Burst mode (disambiguation), a mode of operation where events occur in rapid succession
**Burst transmission, a term in telecommunications
**Burst switching, a feature of some packet-switched networks
**Bursting, a signaling mo ...
, and sometimes
fully automatic).
Ammunition

They generally store ammunition in detachable
box
A box (plural: boxes) is a container with rigid sides used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides (typically rectangular prisms). Boxes can be very small (like a matchbox) or v ...
or
drum magazine
A drum magazine is a type of high-capacity magazine for firearms. Cylindrical in shape (similar to a drum), drum magazines store rounds in a spiral around the center of the magazine, facing the direction of the barrel. Drum magazines are contra ...
s in order to decrease reloading time, whereas most pump-action and semi-automatic shotguns use under-barrel
tubular magazine
A magazine, often simply called a mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal/fixed magazine) or externally attached (detachable magazine). The magazine functions by holdi ...
s.
Automatic shotgun ammunition choices are slightly limited because the fired shot must provide sufficient recoil energy to reliably cycle the action. This means they are not compatible for use with low powered rounds, e.g.
less-than-lethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be lethality, less likely to kill a living target than c ...
ammunition. The most common
shotgun shell
A shotgun cartridge, shotshell, or shell is a type of rimmed, cylindrical (straight-walled) ammunition used specifically in shotguns. It is typically loaded with numerous small, spherical sub-projectiles called shot. Shotguns typically use a ...
used in combat shotguns contains
00 buckshot, 8 to 10
lead balls, which is very effective against unarmored targets.
Strengths and weaknesses
A standard shotgun shot fires multiple small projectiles at once, increasing the chances of hitting the target. Shotguns have a short effective range of about , but provide a lot of firepower at close range.
Automatic fire enhances these effects, due to the increase in the rate of fire.
Automatics typically have much shorter barrels than
pump-action shotguns (especially hunting shotguns).
Short-barreled shotguns have a very high chance of hitting close range targets, and can even hit multiple targets in one area, which is ideal for close combat situations. Long-barreled guns as long pump action shotguns are more accurate and have increased range, which is ideal for hunting and sporting purposes.
Automatic shotguns are generally viewed as less reliable than manual operation shotguns, because there are more moving parts and increased chances of error.
If any one piece fails, it will most likely halt the operation and cause damage to the weapon and/or user. Automatic weapons are also more susceptible to jamming
and negative effects from dirtiness.
Use
Automatic shotguns are intended for use as military
combat shotguns. They typically have a high
rate of fire and relatively low
recoil
Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, for according to Newton's third law the force requ ...
, making them ideal for engaging targets in a fast-paced, close range combat situation.
They are able to fulfill many different combat roles due to the wide variety of shotgun ammunition available.
Automatic shotguns have not seen much use in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, but have been slightly more popular in some other countries.
List
*
AAI CAWS
*
Atchisson AA-12
The AA-12 (Auto Assault - 12), originally designed and known as the Atchisson Assault Shotgun, is a fully automatic combat shotgun developed in 1972 by Maxwell Atchisson. However, the original development by Atchisson seems to have produced only ...
*
Daewoo USAS-12
*FAS-173
*Gordon CSWS
*
Heckler & Koch HK CAWS
The Heckler & Koch HK CAWS (Close Assault Weapon System) is a prototype automatic shotgun—designed as a combat shotgun—co-produced by Heckler & Koch and Winchester Repeating Arms Company, Winchester/Olin Corporation, Olin during the 1980s. It ...
*LW-3
*
Pancor Jackhammer
*
Saiga-12 (if converted to fully automatic fire)
*
Smith & Wesson AS-3
*Remington 7188
*
Vepr-12 (when converted to full auto)
See also
*
Combat shotgun
*
List of combat shotguns
This is a list of combat shotguns: shotguns that have been designed for use in warfare, and have been used by law enforcement or military units.Valtro PM-5 12 gauge pump-action removable box magazine (typically 7 rounds) Used by the French Navy
T ...
*
List of shotguns
Shotguns have traditionally fired iron, Rock (geology), stone or lead shot stored in large shells that are normally loaded.
See also
*Semi-automatic shotgun, Assault shotgun
*Automatic shotgun
*Combat shotgun
*List of bullpup firearms
*List ...
*
Riot shotgun
*
Semi-automatic shotgun
References
{{Firearms
Paramilitary weapons