This Ruger manufactured third variation 5 1/2" long barrel is for the old model 3 screw Single Six single action revolver with an adjustable style rear sight and is in very good condition retaining the majority of its original blue finish with some thinning from holster wear and honest use. The bore is bright and rates excellent.  (file photo)

Markings: This barrel has the later markings after the company became Incorporated: Sturm, Ruger & Co., Inc. / Southport, Conn. U.S.A.