I called Hodgdon Powder Co. today spoke with tech reference using Trail Boss in my Uberti 1885 45-90. His advice was lay the bullet next to the case, mark it with a pencil fill it with Trail Boss and that is a Maximum load. Multiply it by .7 to get 30% for a starting load. He also stated you could fill the case up with Trailboss and light it up and not cause any damage........