Hey fellas, Im into guns as much as I am knives but lets face it, theres a little more work that would go into building a custom gun from scratch so I'll stick to learning the knife craft and buying my guns. BUT I see a lot of work coming from some of the gun folks with color case hardening. I very rarely see this on knife works but think its just superb looking. Turnbull Manufacturing just advertised on their facebook page a color case hardened blade. Just wondering if this is NOT an approved practice? OR just not done that often for what ever reason.