Patented in 1855 by James Butterfield, this revolver is a 5-shot, .41 caliber percussion revolver with a brass frame and 7.5 inch barrel. Aside from its somewhat unorthodox grip configuration, what makes it interesting and unusual is that it was designed to automatically feed pellet primers, obviating the need to cap the cylinder manually after loading.
Butterfield got a contract to make 2300 of his revolvers for the Ira Harris Guards (later renamed the 5th and 6th New York Volunteer Infantry), but the contract was ended prematurely and only 640 guns were produced. Details aren’t available, but one would suspect that the money simply ran out. Thanks in part to the truncated production, these are quite rare secondary military pistols today.