I think the difference between #10 & #11 is (in thoery) size, not power. Maybe fitting better on the nipple would allow more flash into the chamber? but I have no way of knowing or testing that bright idea. The #11 & #11 magnum definitely have a different power though & from my limited experience the same size, at least in the few tins I've tried. Pyrodex is a little harder ti ignite supposedly so maybe magnums wil give a better result with it than regular ones?
Allan Quatermain: “Automatic rifles. Who in God's name has automatic rifles”?
Elderly Hunter: “That's dashed unsporting. Probably Belgium.”