Let me start off by saying I am NOT discussing the making of black powder, as in how to do it, but the quality, distribution, and diversity of manufacturers in the days before smokeless became the king of the hill. As such, powder burning speed varies greatly depending on how well the mixture is integrated through the wetting process, and how fine the granules are. It's relatively simple stuff to make when you have the raw materials. In the old days, it really wouldn't be that efficient to ship it vast distances. My question is really one for historical context; how diversified was the manufacture? Did pretty much every town or county have a manufactory? How about the mountain men, living far from civilization? Did they make their own stuff? Quality and burning speed consistency can vary greatly based on a whole host of reasons. I mean, given the above, all powder is not the same.