The Metcalfe device was invented by Ordnance Department officer Henry Metcalfe and patented in 1875. The blocks were issued pre-loaded and carried on the belt. Only 100 Model 1870 and 1,008 Model 1873 rifles were fitted with the devices. 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 an "ESA" cartouche. The serial number falls in early 1876. The included block has a paper wrap with tear off string and is marked: "8 RIFLE-BALL/Calibre .45. 60 Grains Musket Powder./Put up at Springfield Armory, Feby, 1876" on the back and "CARTRIDGES/Bullet, .408 Grains./Made at Frankford Arsenal, June, 1875" on the front. Also includes a copy of an evaluation letter from the late Peter A. Cardone of Antique & Collector Arms dated October 19, 1993.

Fine with a blend of fading original blue mixed with mottled brown patina, over half of the original case colors, minor oxidation, and general moderate age and storage related wear including some dents and scrapes on the stock which has had an added coat of varnish. The cartridge block remains unopened and has a partially torn seal. Mechanically excellent.