Springfield model 1870  The Springfield model 1870 was one of several model "trapdoor Springfields", which used the trapdoor breechblock design developed by Erskine S. Allin. The model 1870 was a minor improvement to the Springfield Model 1868, and retained most of the Model 1868's features. Note: Springfield model 1870 may also refer to the Springfield rolling-block U.S. Navy Rifle, employing the Remington Arms Company rolling block design, and manufactured under a royalty agreement with Remington, for use by the United States Navy as a shipboard small arm. The trapdoor Springfields had originally been designed as an inexpensive method of converting Springfield Model 1863 muskets into breech loading rifles, which dramatically improved their rate of fire from about four shots per minute to about a dozen shots per minute. The original trapdoor Springfields had replaced only the firing mechanism, and had used a barrel liner to reduce the caliber from .58 to .50. This barrel liner proved to be unreliable in the field, and later trapdoor Springfields, like the model 1870, abandoned the barrel liner method and used newly manufactured barrels instead. There were two versions of the Springfield model 1870, which differed slightly from each other. The first version was produced in 1870 and 1871. The rear sight was improved, and the receiver was shortened to create the model 1870 receiver. The rear sight on the first model 1870 was almost against the receiver. 1,000 of these rifles were manufactured. The second version was produced in 1872 and 1873. In this version the rear sight was moved up so that it was about half an inch away from the receiver. This version also featured a double shouldered ramrod, which differed from the first model 1870 that had used the Model 1868's ramrod. The second version model 1870s also had a long high arch on the underside of the breech block, which differed from the first version which had a shorter arch identical to the Model 1868. 10,000 of the second version were manufactured. A shorter carbine version was also produced in 1871. Approximately 350 of these were manufactured. All model 1870 Springfields (the carbine version as well as both versions of the rifle) used the .50-70-450 cartridge. Wild Bill Hickok, the famous gunfighter, used a variant of the Springfield model 1870. The "Hickok rifle" has a 29 5/8 inch barrel, which is longer than the carbine version's barrel and shorter than the rifle version's barrel, and also has a Kentucky rifle style sloped butt.