RE: bullet seating depth?
Another technique from yesteryear that is coming back in the riflesmithing world is the grinding of chamber reamers without a throat. So the reamer cuts the body, shoulder, and neck. Then, as a second step, you cut the throat with a throating reamer - custom tune the throat length to a specific bullet/seating length. Many of the old reamers from P.O. Ackley's collection at the Trinidad Gunsmithing College are cut this way.