It has been my experience that cutting thru a cased finish sometimes leaves a rough edge to the new cuts (burrs). These burrs are normally removed by polishing with wet or dry paper which also removes color. Cutting medium to heavy lines isn't to bad BUT, trying to cut fine shade lines is rough on a graver as the point keeps breaking & skids across the surface of action leaving scratch.
My understanding is that there is extra strength added to action. The tech/engineers at the Colt factory maintained that the color cased action was stronger that a blued or nic. plated action. FWIW, Ken
