The specialized 60 degree shoulder sight base cutter is engineered to create dovetails compatible with both standard Colt factory and mil-spec 1911 Autos, as well as replacement sights such as the Wichita Hi-Mount, older Bo-Mar and others featuring a 60 degree shoulder. Certain manufacturers utilize a 60 degree dovetail for their rear sights and we offer a cutter specifically designed to accommodate these specifications. For low-mount adjustable sights, please refer to the standard sight base cutter detailed on this page. The actual cutting diameter is 0.33 inches, necessitating multiple passes to install most sights. This design choice accommodates factory variations in base width and milling tolerances.