I'm going to start looking for barrels, for the action I have, It has a greener cross bolt and double underlugs and a hidden third fastner aft of the crossbolt. It's also very tight. With judsons suggestion of using the 450#2, the proof will only be 75% of the original proof in terms of breech thrust, so I think it will do fine. Back to barrels, should I have the maker short chamber and thread the shank or will that add problems down the line?