Designed specifically by Colt to fill the need for a large heavy-duty powerful revolver, that was accurate. Trooper filled that need. Offered with 4" or 6" barrel, blued or nickel finishes and checkered walnut grips. Trooper chambered for .38 Special, .357 Magnum and there is a .22 rimfire version for target shooters. Manufactured between 1953 and 1969. NOTE: Add 10 percent for .357 or .22.