 Although Springfield Armory had previously purchased 7.65×21mm Parabellum pistols for two separate field trials in 1900 and 1902, U.S. authorities had rejected the 7.65x21mm cartridge as insufficiently powerful for military use.In 1904, a small number of Parabellum pistols were tested in the then-new, more powerful 9×19mm round, but U.S. authorities again rejected the pistol.By this time, numerous adverse combat reports of insufficient stopping power of the Army's Colt .38 caliber revolvers used in the 1899-1902 Philippine Insurrection and the published findings of U.S. Army personnel obtained from the Thompson–LaGarde Tests resulted in a requirement for a military handgun in .45 (11.25mm) caliber.