@Selair_chapman,
The Artilleryman magazine is published quarterly; 37.95/year and will connect you with everything and everybody muzzle-loading artillery related, both old and reproduction. An excellent resource, I see ebay has past issues for sale too. I urge you to do some serious study on the subject before firing your piece. Ideally, edited work, and certainly not you tube in this instance. Regarding safety, the publication I refer to also has reports of any recent live-fire accidents. Too, you might look for South Bend's past catalogs, another great resource including lots of photos showing the manufacture of their pieces.