Colt Walker of Texas had been the major purchaser of the early Paterson Holster Pistol (No. 5 model), a five shot cal .36 revolver, and Samuel Walker became familiar with it during his service as a Texas Ranger. In 1847, Walker was engaged in the Mexican-American War as a captain in the United States Mounted Rifles. He approached Colt, requesting a large revolver to replace the single-shot Aston Johnson holster pistols then in use. The desired .44-.45 caliber revolver would be carried in saddle mounted holsters and would be large enough to dispatch horses as well as enemy soldiers. The Colt Walker
Colt 1851 Navy Revolver rimfire or centerfire cartridges, the "Colt Model 1851 Richards- Mason Conversion" by the Colt factory. Famous "Navy" users included Wild Bill Hickok, John Henry "Doc" Holliday, Richard Francis Burton, Ned Kelly, Bully Hayes, Richard H. Barter, Robert E. Lee, Nathan B. Forrest, John O'Neill, Frank Gardiner, Quantrill's Raiders, John Coffee "Jack" Hays, Wallace, Frederick Townsend Ward, Ben McCulloch, Addison Gillespie, John "Rip" Ford, "Sul" Ross and most Texas Rangers prior to the Civil War. Use continued long after more modern cartridge revolvers were introduced. The Ottoman Empire used the revolver as late as the Russo-Turkish War of 1877–78 even though