when the united states joined world war i, they did not have very good machine guns. one reason for this was because there was no military doctrine for their use. the u.s. declared war on germany on 6 april 1917. at this time, the commanders were told that the u.s. only had 670 m1909 benet-mercies, 282 m1904 maxims and 158 colts, m1895 to fight the war. after a lot of arguments, they decided that the u.s. would have to build up more american weapons. however, until then, u.s. soldiers would have to take what the french and british could give them. the machine guns given to the u.s. by the french were often not very good. they also fired different cartridges from what the u.s. soldiers usually used. this meant that soldiers and machine gunners had to be given different kinds of cartridge.