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 Single Action Army two mounted "Cowboys" at the Gunfight at the O.K. Corral were armed with this rifle and pistol combination. .38-40 and .32-20 (.32 WCF) also qualify as "Frontier Calibers" because 1873 and 1892 Winchesters were made in these calibers, offering the same convenience as the 44-40 (44WCF) caliber, namely using the same cartridge in both revolver and rifle. The Colt Bisley was introduced in 1894 as a target pistol. The name Bisley came from the famous firing range in Bisley, England. The Colt Bisley can be distinguished by the longer grip, the wider hammer spur, and the wider trigger. The distinguishing