The Metcalfe device was invented by Ordnance Department officer Henry Metcalfe and patented in 1875. The blocks were to be issued pre-loaded and carried on the belt. Only 100 Model 1870 and 1,008 Model 1873 rifles were fitted with the device. The Model 1873 examples appear to have never been issued and are assumed to have been nearly entirely disposed of via disassembly or sales. The rifle also has the other standard Model 1873 markings and features, including the high arch breechblock and circle script "P" cartouche behind the trigger guard. The serial number falls in the estimated range for the experimental rifles from 1876. There is a hand-scratched marking on the lock over the Springfield markings that appears to be "MASS." The included Metcalfe block contains eight internally primed .45-70 cartridges. A blued "US" socket bayonet with black steel scabbard and a leather frog with brass "N.G.P." (National Guard of Pennsylvania) plate and "42" stamp are also included.

Good with mostly mottled brown patina, traces of original finish, minor oxidation and pitting, and general marks and scratches. The stock has numerous scrapes, dents, and gouges; a crack behind the lock, and general wear from use and storage. The bayonet retains most of the original blue and has moderate edge wear and some oxidation. The scabbard has nearly all of the Japanned finish, and the leather is good with mild flaking. Mechanically fine. This rifle appears to have been together for a long time, although there is no way to verify! Nonetheless, a solid representative example!