Best thing I ever did was get away from a wood Vice to an aluminum bushing Vice. On cerakoted barrels I use a piece of paper from an auto trader and it never slips or Mars. I just removed a stock Remington barrel that was coated that I had a 4 foot breaker bar on and it lifted my 350 pound table off the ground trying to remove the barrel. Not a Mark to be seen
E-Z custom bushings...
Piece of cardboard with a hole cut diameter of the breech cylinder.
Rifle upright, action held in a padded vise. Slide the cardboard down, tape it place around the bottom to create a seal around the barrel/cardboard.
Slide a steel or aluminum bushing down the barrel, OD to match your barrel vise and ID slightly larger than the widest part of the cylinder (if tapered).
Center it up, melt some Cerrosafe and pour it into your "mold".
Let cool, remove from barrel and slit down the middle with a bandsaw. Perfect fit, no crazy taper-turning to try to match profile on the lathe.