Amen to that J. Hall, when you're dealing with the business end of a shotgun you can't practice enough keeping one's place!!!! With a double you are always dealing with a loaded barrel and there have been people on other muzzleloading boards that have removed the cap from the nipple and the cap has left enough residue of primer paste (Fulminites of Mercury?) to discharge that load.
Muzzleloaders are not for the timid!!!!
All the best