The Single Six has been with us for over 60 years now, and continues to be a highly popular plinking, trail and small game gun. Story offers conversion cylinders to increase the potency of these fine little firearms. This 17 caliber barrel is a requirement for Story's 17 HMR and HM2 conversion cylinders. Produced by Green Mountain for Story. Button rifled with a 1 in 9" twist. Drilled and tapped for the ejector rod housing. Barrel face is left long for final fitting. Includes an installed front sight. 4140 chrome moly steel with a black oxide finish. 6" long. Barrel installation requires specialized tools and knowledge, so gunsmithing installation is recommended.