O'key, I've been given this source and been told Ball Mill Method is the way to go. Also I've been told changing type of
charcoal it's possible to get weaker or stronger powders for smooth and rifled guns. As heavier wood charcoal made from, as stronger powder. Lignum Vitae comes to mind in this case...
Take care and do not burn down your own city!

http://www.wfvisser.dds.nl/EN/bp_making_EN.html

Geno.