I have engraved several M21s, mostly for the custom shop years ago. They never let one out of their hands that was not already heat treated, so yes, they are tough to engrave but by no means impossible. Bruno Pardee, who at one time ran the USRAC custom shop, told me their specs called for a Rockwell hardness of 42 to 46 and that they tried to keep them at the 42 number so they could be engraved. Anything over about 37 is starting to be hard to cut. The M21 cuts smoothly but takes a lot more time and tool resharpening.
I might add, using a pneumatic hammer and carbide tool bits helps a lot.
I can see this one now, 20ga/44-40 Cape Gun! What fun!
Last edited by SamW; 12/08/12 07:54 PM.
