The Model 1902 is a semi-automatic pistol developed by famous American firearms designer John Browning and produced by the Colt's Patent Firearms Manufacturing Company in the early 20th century. The Model 1902 was not a new design, but rather an incremental improvement upon the nearly identical M1900, and would transition from the 1900 into three distinct but related pistols with the same action and cartridge, the 1902 Sporting Model, the 1902 Military model, and the 1903 Pocket Hammer model. The 1902 Sporting model was so similar to the 1900 that it continued the serial number range, while the 1902 Military Model featured a different serial range as did the 1903 Pocket Hammer model. The 1902 Military Model featured a square and lengthened grip frame with an additional round in the magazine, while the 1903 Pocket Hammer featured a shortened barrel and slide but retained the Sporting model grip frame. The Colt M1905 .45 ACP pistol would be derived from the same lineage, also with a different serial number range.