 Over 50,000 Model 1868 rifles were manufactured, chambered for the .50-70 450 cartridge.This model served as the basis for the definitive Model 1873 "Trapdoor Springfield" series of rifles in .45-70-405 caliber, which was adopted in 1873 as the standard military longarm of the United States armed forces for the next 20 years.This model is unique in the 'trapdoor' series by being marked with the actual year of manufacture (1868, 1869, or 1870) on the breech-block.