I would dimple the .648 ball, load it bare (right on top of the powder) about a hundred grains of 2F, or even 1F, and hold it in place with some hornets nest, towe, or a piece of old wool blanket, with a little venison tallow, or bear grease.
This shoots well, is fast to load, and rarely sets fires. It is pretty easy on the shoulder too. With no wads, cards, or cups, it doesn't run the pressure up very high either.
Hungry Horse