The Springfield Model 1873 was a popular gun for infantry use. This change improved the muzzle velocity that could be achieved by the Model 1873 (the smaller bullet was also lighter) and the greater barrel twist improved the accuracy of the Model 1873 over the Model 1866 and Model 1868. 50-70 Government cartridge originally designed for the Springfield Model 1866. 45in (11.4mm) bullet was smaller than the. 45-70 Government, the first instance of this cartridge being used in any rifle. Furthermore the front barrel band was redesigned to improve the sling swivel (where the sling was attached to the rifle) to allow a stacking swivel to be attached (to allow large numbers of Model 1873s to be stacked together in armories).

Major aesthetic changes were made to the Model 1873 with parts such as the stock given rounded edges, screw heads rounded off (and rivets replaced by screws), metal parts blackened (or occasionally browned) and the ramrod being redesigned to improve the grip when using it to clean the barrel. Other mechanical features to be changed from the Model 1868 included the hammer, which was rounded off (to improve the contact with the firing pin, and reduce the potential to dislodge it) and rear sight, which was changed and moved further along the barrel (improving the accuracy of the Model 1873 when using the sights). 45-70 Government cartridge, which fired a. It was also given a tighter 1:22 rifling twist (producing a greater spin on the bullet than the Model 1868 was capable of) and the bore was changed to accept the smaller. The barrel of the Model 1873 was made of a low grade steel, rather than iron as the Model 1868 (and earlier Springfields, all the way back to the Model 1795 Musket) had used. The Model 1868 would also form the basis of the Model 1873, although with several significant changes. Allin for the Springfield Model 1865 (named, occasionally, the 'First Allin') and had been improved through the Model 1866 and Model 1868.

This mechanism had originally been designed by Erskine S. The Springfield Model 1873 used the heavily refined hinged breechblock mechanism, often referred to as the 'Trapdoor' because of its hinge located ontop of the barrel which opens vertically.

1873 springfield trapdoor carbine parts