Wayne - they are talking about long tons here, as in 2,200pounds per, so the pressures they are talking about are well under modern shotshell smokeless levels.
: I did well with both 4756 and 7625, 4756 being the slower burning of the two. I was so impressed with the velocities Hogdon was getting from it's longshot, that I mentioned it just hoping something was similar for you. Of course, the main problems come from getting proper wad pressure and getting the various slower powders to ignite and burn properly. Plastic wads supposedly eliminated the wad pressure loadings with shot, but since we use built up wad columns in RB loads to get proper height, we're back to loading the way the 'old timers' had to, wiht wad pressure.
: Vancouver is OK if you like crowded areas, wierd people and rain. I prefer fresh air and sunshine. I lived in the Vancouver area for a number of years. It is truely beautiful when the sun shines, though.
: When working from load data derived from shotshells and shot, we must tread softly, and carefully. A chronograph helps us stop when we've arrived at a suitable level of power.
; I would check out all or the data I could on available powders and choose one (or more) that developed the best velocities at the lowest pressures. These will normally show as being high-grain weight charges. ie: 20gr. giving max load at say 1,200fps(trap speed) with 1-1/8oz at 11,000 pounds compared to 28.0gr. giving 1,340fps with 1-1/4oz at 8,800 pounds pressure. The powder developing 1,340fps at 8,800pounds would be perfect for developing ball loads, whereas the 'faster' burning powder isn't.
; Forgot to mention - re: rifling - a fully rifled bore should devlope more breech pressure than a paradox or rifled choke on a smooth bore.