I wonder how people got by with their flintlocks before there were large producers of the stuff along with reliable transportation and chain of supply? If the world were thrown into utter chaos tomorow, of all of the firearms out there, the flintlock would be the last to go obsolete. Think making blackpowdr is difficult and dangerous? Try making smokeless powder or black powder substitutes.

Most likely reason why shops quit being suppliers of BP (by 'BP' I mean real black powder not pyrodex) is that BP is considered to be an explosive and requires special handling and storage, not to mention the hazmat fees for transporting the stuff.