It'll work, but isn't something I'd do. Shoving all that BP through that little hole in the end of the case is going to be really hard on them, probably stretching them pretty bad. The bullets don't carry much lube so you'll have to wipe the bore after every shot. Accuracy will likely be non existant, and then you'll have to figure out how to get the BP fouling out of your cases. I recommend against it, the Swede makes a wonderful cast bullet rifle but not with BP.