Only 300 of these rifles were manufactured around 1870-71 at the Springfield Armory using Sharps supplied Model 1874 actions, serialized in their own range of 1-300. They were used in U.S. military field trials in the search for a new standard issue breech loading rifle. The action has the Sharps patent marking on the left and serial number "67" on the upper tang. The barrel has a standard military front sight/bayonet lug, notch and folding ladder rear sight, no Sharps markings, and serial number "67" on the left at the breech. The forend is held by two barrel bands marked "U" on the right. Single letter inspection marks on some of the small parts, "US" on the buttplate, and a faint oval script "ESA" (Erskine S. Allin) inspector cartouche on the left side of the wrist. The lock is the Model 1874 pattern and has no external markings.