The mold I queyed up in my cart is a 3 cavity aluminum with a troughed spur plate.
I'm thinking coww with 2% tin for the general run of things. Powder coated.

I probably won't be getting into black powder. There's only just so much will fit between my ears.
I am thinking something like 12 gr of Unique and backer rod.
10 gr of Unique and a 400 gr cast from my 480 Ruger SRH 4.5" gives me right around 1000 fps.
More research is needed.