High Quality Content by WIKIPEDIA articles! The Colt Single Action Army (also known as the Model P, Peacemaker, M1873, Single Action Army, SAA, 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 Colt`s Manufacturing Company, and adopted as the standard military service revolver until 1892.