Colt Single Action Army ... The Colt Single Action Army (also known as the SAA, Model P, Peacemaker, or M1873, or Frontier) is a single-action revolver handgun.
The Colt Single Action Army (SAA), also known as the Model P, Peacemaker, or M1873, is a single-action revolver that was developed by Colt for the U.S. Army trials in 1872. It was adopted as the Army's standard-issue sidearm from 1873 to 1892.
The new long-barreled six-shooter, with its .45 Colt chambering, was adopted in 1873 by the Army with an initial order of 8,000 revolvers. Eventually, this would grow to some 37,000 guns.
The US Army’s first service revolver to use metallic cartridges, it replaced the cap and ball Colt Army Model 1860. The Single Action Army was the second metallic cartridge pistol developed by Colt and the first US Army service pistol to chamber the new .45 Colt round.