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
William Mason (Colt) built by Colt. With increased competition from their British rival, Webley & Scott, Colt had Mason design a double-action revolver for them in 1877, the Colt M1877. Following this, Mason once again teamed up with Richards to produce a larger framed version, the Colt M1878 Frontier in 1878. His final design for Colt was the Colt M1889, a collaboration with Carl J. Ehbets for a revolver with a swing-out cylinder. Ehbets continued to perfect the idea for 7 years after Mason left Colt for Winchester. Mason left Colt to work for the Winchester Repeating Arms Company in 1882. While he