Description: Rare and Unique Documented Colt U.S. Contract Artillery Model Single Action Revolver with Un-Numbered Replacement Frame Colt Artillery Model Single Action Army revolver with un-numbered replacement frame, barrel, cylinder and trigger guard. The Ordnance Department purchased 171 unnumbered replacement frames from Colt between 1874 and 1891. The left side of the frame is roll-stamped with the Colt three-date/two-line patent marking initially used by Colt in 1890 at approximately serial number 134,000. "A Study of the Colt Single Action Army Revolver" by Graham, Kopec and Moore states that the Army purchased six replacement frames from Colt on May 4, 1891....