Terry, yes they will still re-proof for black powder guns. Don't ask me what pressure system they mark as I have had barrels back that I think are just marked Black Powder Proof and the chamber length in centimetres and just prior to that I had one marked with a service load in metric that equated to 3 3/4 Dram of powder and 1 1/4 ounce of shot in a 2 1/2" 12 bore. As mentioned, we could do with an up to date book in order to be able to interpret marks.
Dougles, I think; and Smallbore may correct me on this, that the Standard proof pressure is for standard length chambers of either 2 1/2" or 2 3/4" for which they use the same proof load, and the Superior Proof is for 3" and longer chambers using a heavier proof load. That's how I understand it at the moment anyway. Lagopus.....
