 Although the Model 1897 was popular with American troops in World War I , the Germans soon began to protest its use in combat . " On 19 September 1918 , the German government issued a diplomatic protest against the American use of shotguns , alleging that the shotgun was prohibited by the law of war . " A part of the German protest read that " [ i ] t is especially forbidden to employ arms , projections , or materials calculated to cause unnecessary suffering " as defined in the 1907 Hague Convention on Land Warfare . This is the only known occasion in which the legality of actual combat use of the shotgun has been raised . However , the United States interpreted their use of the shotgun differently than Germany . The Judge Advocate General of the Army , Secretary of State Robert Lansing carefully considered and reviewed the applicable law and promptly rejected the German protest . France and Britain considered using shotguns as trench warfare weapons during World War I. The shotgun in question was a double @-@ barreled shotgun , which was not used because they were unable to obtain high powered ammunition and that type of gun is slow to reload in close combat . 
