U.S. Contract Colt Single Action Cavalry Model revolver manufactured in 1887 and inspected by Captain John G. Butler (JGB) and Ordnance Sub-Inspector David F. Clark (DFC). The left side of the revolver grips is stamped with the date "1887" above the script initials "JGB" without the oval border that usually encloses the grip inspection marks. Revolvers with this distinctive JSB inspection mark are extremely rare. The revolver has the late, oval ejector rod head adopted in 1885. The hammer has elongated, bordered knurling on the spur. The barrel, ejector housing, cylinder, trigger guard and back strap have the Colt military blue finish, and the frame, hammer and loading gate are color casehardened. The one-piece walnut grip is oil-finished. The barrel is roll-stamped with "Elongated Block Letter" address: "COLT'S PT. F. A. MFG. Co. HARTFORD CT. U.S.A." in one line. The left side of the frame is roll-stamped with the Colt "Three-Date/Three-Line" patent marking followed by the "U.S." property mark. The small, block-letter "D.F.C." sub-inspection mark is stamped on the underside of the barrel, the bottom of the frame above the serial number, the side of the cylinder and on the bottom of the left grip heel. Small "P" proofmarks are stamped on the underside of the barrel and on the side of the cylinder. The script initials "DFC" surrounded by a rectangle are stamped on the lower right side of the grip. The assembly number "807" is stamped on the inside of the loading gate. The full serial number "119977" is located on the bottom of the frame, trigger guard and back strap. The partial serial number "9977" is stamped on the barrel beneath the ejector housing and on the side of the cylinder. All of the visible serial numbers match.