My early 50's lyman Handbook recomends 27 grains of red dot for 3 3/4, 1 1/4 oz 10 bore loads. This was with card wads. They don't seem bothered by the lack of PSI or FPS data however they called for 70 psi wad pressure. I note that many people don't seem to realize that wad pressure was critical on paper hull, paper wad loads.

bill