Editing Shotgun (section)

===World wars===
The decline in military use of shotguns reversed in [[World War I]]. American forces under [[General Pershing]] employed 12-gauge pump-action shotguns when they were deployed to the Western Front in 1917. These shotguns were fitted with [[bayonets]] and a heat shield so the barrel could be gripped while the bayonet was deployed. Shotguns fitted in this fashion became known as ''[[combat shotgun|trench guns]]'' by the [[United States Army]]. Those without such modifications were known as ''riot guns''. After World War I, the United States military began referring to all shotguns as ''riot guns''.

Due to the cramped conditions of [[trench warfare]], the American shotguns were extremely effective. [[German Empire|Germany]] even filed an official diplomatic protest against their use, alleging they violated the [[laws of warfare]]. The [[United States Army Judge Advocate General's Corps|judge advocate general]] reviewed the protest, and it was rejected because the Germans protested use of lead shot (which would have been illegal) but military shot was plated. This is the only occasion the legality of the shotgun's use in warfare has been questioned.<ref>{{cite journal | author = Bruce N. Canfield |date=May 2004 | title = Give Us More Shotguns! | journal = American Rifleman }}</ref>

[[File:ww2marineshotgun.jpg|thumb|upright|A [[United States Marine Corps|United States Marine]] carrying a [[Winchester Model 1897|Winchester M97]] shotgun during [[World War II]]]]

During [[World War II]], the shotgun was not heavily used in the war in Europe by official military forces. However, the shotgun was a favorite weapon of Allied-supported [[Partisan (military)|partisans]], such as the [[French Resistance]]. By contrast, in the Pacific theater, thick jungles and heavily fortified positions made the shotgun a favorite weapon of the [[United States Marines]]. Marines tended to use pump shotguns, since the pump action was less likely to jam in the humid and dirty conditions of the Pacific campaign. Similarly, the [[United States Navy]] used pump shotguns to guard ships when in port in Chinese harbors (e.g., Shanghai). The [[United States Army Air Forces]] also used pump shotguns to guard bombers and other aircraft against saboteurs when parked on airbases across the Pacific and on the West Coast of the United States. Pump and semi-automatic shotguns were used in marksmanship training, particularly for bomber gunners. The most common pump shotguns used for these duties were the 12-gauge [[Winchester Model 1897|Winchester Model 97]] and [[Winchester Model 1912|Model 12]]. The break-open action, single barrel shotgun was used by the British [[Home Guard (United Kingdom)|Home Guard]] and U.S. home security forces. Notably, industrial centers (such as the Gopher State Steel Works) were guarded by National Guard soldiers with [[Winchester Model 37]] 12-gauge shotguns.