Many years ago, I used to shoot muzzle loaders including pistols, shotguns, smooth bore muskets and my favorite 1861.577 Three Band Enfiield as well as a massive 25mm bore French Elephant Gun.
I used to cast my own lead balls, stamp out wads and cards and, In my area, flint ocurred naturally, so I taught myself to knap flints.
One thing you should NEVER do, is load patched ball bearings. It they hit something solid, they have a tendancy to bounce straight back at you !
I have had the opportunity to handle several pairs of original duelling pistols from the 18th Century
You might find this interesting:
imgflip.com/i/4byiot