One of only 926 Colt Model 1905 Double Action Revolvers purchased by the Marine Corps between 1905 and 1909. The Model 1905 Revolver was the first handgun manufactured specifically for the Marine Corps. This revolver was a New Model Army and Navy revolver with a modified grip frame and distinctive two-piece checkered walnut grips with a rounded contour butt. The butt is marked with the serial number: "No./623" (10623) in front of the lanyard swivel and "U.S./M.C." behind it. The top of the barrel is marked with the two line Colt Hartford address and "AUG.5.1884 NOV.6.88. MAR.5.95" patent dates. The left side of the barrel is marked "COLT D.A. 38", and the circled Rampant Colt is on the left rear of the frame above the grip. The assembly number "138" is stamped on the inside of the grip, the crane and on the yoke. The revolver has no visible inspection or acceptance marks. The revolver has the high polish Colt blue finish on the barrel, cylinder and frame. The trigger and hammer top have a niter blue finish, and the sides of the hammer are polished. The ejector rod and lanyard swivel are casehardened. There is a small removable collection marking on the trigger guard.