effect due to limited space in the jungles and frequent close combat. In the Vietnam War, the shotgun was used as an individual weapon in the American army during jungle patrol and urban warfare like the Tet Offensive. During the Somalian conflict in 1992, the US task forces tested out a new type of Remington shotgun called Ciener Ultimate Over/Under, which was an under-barrel attachment for the standard M16 variants during Operation Gothic Serpent. The idea was for a soldier in an entry team to be able to breach a locked door with the shotgun and then immediately switch to the assault rifle to clear the room. According to the Army Rangers, their verdict was positive for this new type of breaching gun. In operations in post-invasion Iraq, US forces used their combat shotguns to clear out suspected insurgent hideouts in house to house fighting. One notable experimental shotgun used in limited numbers during Operation Enduring Freedom is the XM26 for breaching doors or close-quarter battle (CQB). Characteristics The most common type of shotgun used for this purpose is the manually operated, slide-action/pump-action type like the Remington M870 or Mossberg 590A1. The latter is currently the pump-action of choice for US armed forces, and both have seen service with other militaries. The pump-action type is less prone to malfunction (particularly when dirty) than semi-automatic designs. Pump-action shotguns are also less expensive than their semi-automatic counterparts. Even so, semi-automatic shotguns such as the Benelli M1014 are currently seeing service in NATO-aligned armed forces. Combat shotguns typically have much shorter barrels than shotguns used for hunting. They usually have magazines of modified design to hold more than the 3 to 5 shots normal with sporting or hunting shotguns. Most combat shotguns have tubular magazines mounted underneath the barrel. These are identical to those of hunting shotguns, except for being longer to hold more ammunition. Some recent designs have detachable box magazines. Combat shotguns are mostly similar to the police riot shotgun. The military versions may have provisions to mount a bayonet, and may be fitted with ventilated steel or plastic hand guards over the barrel to reduce the danger of a soldier burning their hand on the hot barrel during rapid fire. Riot shotguns are more likely to trade off increased magazine capacity for decreased size. For example, a combat model would be more likely to have a 51 cm (20 inch)