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
.38 Short Colt .38 Short Colt The .38 Short Colt (.38 SC) / .38 Short Center Fire (.38 SCF) was a heeled bullet cartridge intended for metallic cartridge conversions of the cap and ball Colt 1851 Navy Revolver from the American Civil War era. Later, this cartridge was fitted with a diameter inside-lubricated bullet in the 125–135 grain range. Visually, it resembles a .38 S&W but the case dimensions are slightly different. The .38 Short Colt case is the parent to .38 Long Colt and .38 Special. Remington is one of the few producers of this cartridge today with a 125grs LRN bullet.