英語版のWikipediaには1903のバリエーションについて詳しい記述があった。
これによると最初期からマニュアルセーフティとグリップセーフティはついていたがついていなかったのはマガジンセーフティだけだった。 Type I: Integral barrel bushing, four-inch barrel, no magazine safety, serial numbers 1 through 71,999
Type II: 32 cal separate barrel bushing, 33⁄4-inch barrel; 1908–1910, SN 72,000 through 105,050
Type II: 380 cal separate barrel bushing, 33⁄4-inch barrel; 1908–1910, SN 001 through 6250
Type III: integrated barrel bushing, 33⁄4-inch barrel; 1910–1926, SN 105,051 through 468,789
Type IV: integrated barrel bushing, 33⁄4-inch barrel, magazine safety
Type V: integrated barrel bushing, 33⁄4-inch barrel, military sights, magazine safety on both commercial and "U.S. property" variations. SN 468,097 through 554,446.
There was an M1903 version with a military Parkerized finish, which is otherwise the same as the Model IV, SN 554,447 through 572,214.