effective short range weapon commonly used, with a hit probability 45% greater than a submachine gun, and twice as great as an assault rifle. The ability to use shotgun slugs extends the range and penetration capability of the shotgun. Police officers in the US commonly secure a shotgun in their vehicles, for use when armed resistance is expected or at any time greater firepower than the officer's sidearm is needed. Riot vs. combat shotguns The difference between the riot shotgun and the combat shotgun is blurry, and may be more a matter of application than design. A combat shotgun would be used in military combat situations as a primarily offensive weapon, where a riot shotgun would be used in law enforcement or civilian situations as a primarily defensive weapon. Common additions to a combat shotgun would be provision for attaching a bayonet, and the addition of a ventilated heat shield over the barrel (though this heat shield is a common addition to riot shotguns as well) designed to prevent the operator's fingers from being burned by a barrel heated by multiple shots, and thus to allow the operator to secure a full grip on the weapon while using the attached bayonet, even when the barrel is far too hot to touch (otherwise, there is little reason to enshroud the barrel and hinder the cooling airflow). One or both of these features can be seen on many military long-arms, including the 1903 Springfield, the SMLE, M1 Garand, and Mauser rifles, to name some of the more obvious types. The U.S. Army specifications for shotguns require a metal trigger guard for durability, which reduces the number of "special purpose" models used by police that would also be suitable for the military (the Mossberg 590A1 and Benelli M1014 are the standard-issue pump and semi-auto shotguns currently in service; the standard Mossberg 500 and 590 models, and most variants of the Remington 870, have plastic trigger groups). Riot shotguns are also more limited in range than combat shotguns by the nature of their use. A combat shotgun is considered effective out to 75 yards (70 m) because on average at least 1 pellet of a 9 pellet 00 buckshot load will hit a human sized target at that range. This is enough to degrade the combat effectiveness of an enemy soldier, but it is not enough to reliably disable an assailant in a defensive