I did a small amount of cutting on one, just a logo, It was hard cutting but not impossible. It was just lines, no flare cutting. I used 105º cmax graver. I can't remember my face angle but it was between 50-55.
i owned a tc 44 magnum of regular steel. did some scratch testing on it and decided not to engrave it. but at that time i wasn't using much in the way of really good graver steels.