It's difficult to believe that modern production black is in any way inferior to what was available pre-smokeless.
Unfortunately that is just not the case, well at least to a large extent. Several individuals (Sherman Bell, Ross Seyfried, and others) have done extensive testing with modern black powders and have found them to be severely lacking to what was available to shooters in the 19th century.
Even without obviously having original blackpowder to test, what they do have is the documented original loads which were used, specifically for double rifles, where the type and amount of powder is extremely critical for regulation.
While blackpowder my seem simple, the composition, source, and quality of it's three ingredients can widely vary between makers today.
