text: The Colt Single Action Army, also known as the Single Action Army, SAA, Model P, Peacemaker, M1873, and Colt .45 is a single-action revolver with a revolving cylinder holding six metallic cartridges. It was designed for the U.S. government service revolver trials of 1872 by Colt's Patent Firearms Manufacturing Company – today's Colt's Manufacturing Company – and was adopted as the standard military service revolver until 1892. The Colt SAA has been offered in over 30 different calibers and various barrel lengths. Its overall appearance has remained consistent since 1873. Colt has discontinued its production twice, but brought it back due to popular demand. The revolver was popular with ranchers, lawmen, and outlaws alike, but as of the early 21st century, models are mostly bought by collectors and Cowboy Action Shooters. Its design has influenced the production of numerous other models from other companies. The Colt SAA "Peacemaker" revolver is a famous piece of Americana known as "The Gun That Won the West".
  In 1889, Colt introduced the Model 1889, the first truly modern double action revolver, which differed from earlier double action revolvers by having a "swing-out" cylinder, as opposed to a "top-break" or "side-loading" cylinder. Swing out cylinders quickly caught on, because they combined the best features of earlier designs. Top-break actions gave the ability to eject all empty shells simultaneously and exposed all chambers for easy reloading, but having the frame hinged into two halves weakened the gun and negatively affected accuracy due to lack of rigidity. "Side-loaders", like the earlier Colt Model 1871 and 1873 gave a rigid frame, but required the user to eject and load one cylinder at a time, as they rotated the cylinder to line each chamber up with the side-mounted loading gate.