.357 .38 Pistol Handgun Chamber Flex-Hone 400 Grit Mag Magnum Cylinder Hone Diameter of shaft for use with .357" and .38 caliber bores Honing your handgun cylinder will result in a smoother, cleaner surface that is free from machining imperfections and less prone to fouling and corrosion. The end result is a more polished smooth bore with a beautiful finish. 3" Overall Length., Abrasive part of hone is 1-5/8" along shaft The surface will be more regular, hold oil and lubricants better and have a beautiful finish.