A riot shotgun is a shotgun designed or modified for use as a primarily defensive weapon, by the use of a short barrel and sometimes a larger magazine capacity than shotguns marketed for hunting. The riot shotgun is used by military personnel for guard duty and was at one time used for riot control, and is commonly used as a door breaching and patrol weapon by law enforcement personnel, as well as a home defense weapon by civilians. Guns of this type are often labeled as breaching shotguns, tactical shotguns or special-purpose shotguns to denote the larger scope of their use; however, these are largely marketing terms. Characteristics The primary characteristic of a riot shotgun is a "short" barrel (generally 14 to 20" long; 18" is the shortest length available to civilians in the U.S. that is not subject to additional federal ATF regulation) which makes the shotgun more compact and easier to handle, easier to stow inside a police vehicle, and more suitable for quick aiming at (close) stationary targets. Generally they have an open (cylinder-bore) choke, to permit the shot to spread quickly and to allow use with other types of projectiles, and they may be equipped with bead, rifle, or ghost-ring sights. Riot guns are most often pump-action due to this design's lower cost and higher reliability, although in recent years a number of semi-automatic shotguns designed primarily for defensive use have become available and are used by military, law enforcement and civilians alike. Most riot guns are chambered in 12-gauge and can handle either 2.75" (70 mm) "standard-length" or 3" (76 mm) "magnum-length" cartridges. Most non-shotshell loads, such as less lethal ammunition like bean bags, are made only in 12-gauge. However, 20-gauge and .410 shotguns in riot gun configuration are available. Smaller bores are popular for home defense, as the reduced power and recoil make them more suitable for less experienced shooters who may be more recoil-sensitive. While most hunting shotguns hold between 2 and 5 shells (often 3 shells, to comply with U.S. regulations for migratory bird hunting), riot shotguns can have a magazine tube as long as the barrel, allowing for 6 to 10 shells to be loaded depending on the model, barrel length, and type of shells loaded. Standard-capacity magazine tubes are also used on riot shotguns. For example, the popular Remington 870 Police model riot shotgun often ships and is used with