In 1871, Springfield Armory converted approximately 1,108 Burnside-Spencer carbines by fitting the actions with rifle length barrels chambered for .50 rimfire ammunition with three-groove rifling and adding the Stabler cut-off device. The armory also refurbished the parts and added a nearly full length forearm with two barrel bands and a slotted cleaning rod. Spencers were easily among the most advanced weapons of the Civil War and remained in use during the late-19th century Indian Wars in the hands of both the U.S. Army and various Native Americans. These rifles were apparently manufactured to utilize unserviceable Spencer carbines and excess Springfield musket components. Serial number "28713" marked on the top of the receiver and the left breech of the barrel. It retains the carbine sling bar and ring, and Stabler magazine cut-off. Oval script "ESA" (Erskine S. Allin) inspection cartouche stamped on the left wrist of the stock behind the sling bar.