Wild Willi:
One of my favorite loads for my 45-75 is from Ken Waters book on loading. It is using 2400 rifle powder and at 22.0 grains. I put a small tuft of kapok on the powder to hold that stuff on the primer. i have never had any problems with this load and continue to use it. The other load that seems to work in my rifle is 72.0 grains of Swiss 1½ Black powder. Here again, my rifle likes both of these loads. As far as cases goes I use 50-90 Sharps brass with no problems. Some of the first stuff, tho, I had to turn down the rims on my lathe so they would chamber but with the new stuff, all works. Hope this will help you out. By the way, in closing, The alloy that I use, I got off the back of a box of original factory ammo and that is 16:1 ratio. I use it and my rifle seems to be happy with it.