11,470 of these innovative rifles were manufactured for the U.S government in 1863 and 1864 within primarily the 700-11000 serial number range. It has a blade front sight that doubles as a bayonet lug, six-groove rifling, three barrel bands, a replacement U.S. 1855 pattern three-leaf rear sight, the three-line Spencer address and patent marking on the top at the breech, and smooth buttstock with the standard tubular magazine inserted through the buttplate.