bought a small cannon .75 cal barrel length 9 1/2 inch. can I use pyrodex which I have or do I need black power. If I need black power with such a large bore and short barrel can I use FFG
Reloading / load data with regard to propellant charges is a topic of discussion not allowed on the IAA forum. I would check one of the reloader forums such as Cast Boolits for help with your question.