1873 saw the introduction of two world famous cartridges which are still with us today, both in .45 cal. Namely the .45 Colt & the .45-70 US goverment. Trapdoor Springfields from 1866 until the introduction of the .45-70 had been built in .50-70 cal, except for the very first ones which were in a .58 rimfire to utilize the existing bores of the converted rifled muskets. Model 1866 Trapdoors used the original bbls bored out & lined to .50 cal but subsequent models were built from "Scratch". Any gun used p;rior to 1873 would not have been a .45-70. There were a number of single shot breech loaders introduced during the War Between the States, but the trapdoor Springfield was not among them. It saw the light of Day "After" the war, the design of a Springfield Armorer, Erskin Allen.
