Daryl,
Thanks.....the crown is a little heavier than the ones you have shown, but it seems to work great. I made a drawing die quite some time ago to make brass, copper, and / or silver tubes from sheet. I used the same type of radius on the muzzle radius cutter.
Craig,
I don't think niter bluing the rifling would hurt it any. Not the same as rust browning or bluing.
Rudyc,
When my daughters were teenagers (and, of course, knew EVERYTHING) and thought something I said was ridiculous, they would often mutter to themselves as the conversation was concluding that "you don't have to be a rocket scientist to figure that out, Dad". Now that they are past 30, I think they understand that with respect to a lot of things in life, rocket science would be the easy part.