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
Starr revolver Starr revolver A Starr revolver (Starr DA) is a double-action revolver which was used in the western theater of the American Civil War until the U.S. Ordnance Department persuaded the Starr Arms Co. to create a single-action variant after discontinuation of the Colt. The company eventually complied, and the Union acquired 25,000 of the single-action revolvers for $12 each (). However, the price paid by the government for the DA army revolver was $25. The State of Ohio purchased 500 of the .36 Caliber Navy version for $20 each. The Starr DA .44 cylinder holds in each chamber of powder,