.450 Calibre Rare 1878 Colt Frontier Six Shooter Double Action Revolver. Colt 1878 Double Action revolver shipped to the London Agency around 1880. Barrel as 5 1/2-inch, the finish as blue and the caliber as ".45/c". The revolver has black, hard rubber 'bird's head' grips. The top of the barrel is roll-stamped: "COLT'S PT. F.A. MFG. Co. HARTFORD CT. U.S.A. DEPOT 14. PALL MALL LONDON." in one line. Incredibly low serial Number being 11. A must for any Colt Collector!