lancaster;

I can't speak for the filing, but I know of some that are hammered to fit.

I'm not sure if a mandrel of some kind is used?

This is really quite a wonderful project. I've long wanted a 9,3x53R but will likely have to enjoy the concept vicariously thru yours. I do have the duplicator of ballistics in the 9,3x57 with which I am, so far this year unsucessfully, chasing elk.

Keep posting.

I can't wait to see the whole thing; lock, stock and barrel.