The FIFTEENTH Century ?? Well, then I stand corrected. LOL
That is much earlier than I thought. Apparently, the meal powder continued to be made for certain gun barrels even with the knowledge of the advanced, more powerful corn powder. Essentially, waiting for barrel development to catch up. Makes sense.
Which, makes it very curious, as Richard mentions, that many of the Indian Torador barrels had the larger than bore size powder chamber at the breech with the constriction to keep the projectile a small distance away from the powder, allowing more oxygen in the chamber, - and were still building barrels this way in the 19th Century. Although the breech wall thickness on these barrels are very thick and heavy on these barrels. Possibly able to handle the more powerful corn powder (?) The locals also thought this barrel design was more accurate.
A few years ago I read of a test that was performed. The shooter used an original 1880's U.S. Springfield Trapdoor Rifle, and a mint condition, unopened box of original U.S.Government 45/70 black powder loaded ammo.
Also, another box of hand loaded 45/70 ammo using the same volume, bullet weight, etc. (70 grs. FFG I believe) using today's sporting black powder. The result was about a 15 percent increase in velocity and accuracy. Of course, this did not surprise most observers. Even taking into consideration the age of the powder in the original ammo, it's interesting to note that today's sporting black powder is more powerful than the same powder made as late as the 1880's.
As long as we are on the subject of powder, I thought I would post this photo below. A short while back I bought an Albanian Tanchika long gun that still had a load in the barrel. Fortunately, in this case I was able to extract the load from the barrel without disturbing the contents. The powder is of the corn variety, but the grains seem a bit inconsistant. Even though I traded the gun, I still have the contents. Interesting to see how they loaded the gun. The ball was considerably undersized which allowed me to keep the contents in such good condition after the extraction.
Rick