Like I said, we make way too much about service vs. proof pressure. As a personal choice I go for lower than service pressure levels in my loads. I can easily find 12 loads in the 5,500 to 7,000psi which handle almost all my shooting needs. For the 20 I bump it up to 8,000 to 8,500psi but do not get excited about 9,000psi. If you reload that gives you a ton of loads to draw from even in these times of difficult to find powders. Factory pressures for American shells are loaded to SAAMI safe levels which are higher. Unless I know for certain what they factory pressures are I just go with my re-loads or CIP approved ammo. Every shell I have loaded on my shelves are low pressure loads, with the exception of a few small batches of loads for hunting situations and they are clearly marked on the primer end. You might need to check if it is 2 1/2 or 2 3/4" at most and my pressures are so low that is not even that big of a deal. I have been much more relaxed about "service pressures" ammo for my classic doubles since I went to uniform loads. The shot size may change depending on intended use, but a 1150fps, load low pressure load, is safe in any gun I own and shoot. About as simple as it can get. I can go down to 1100fps and a few go 1200 but nothing so silly as the current rage of 1450fps ammo which seems to be the current default shell everyone seems to use.
