Powder keg, had several "failure to fire" problems with the #11s. Had drilled out the #11 nipple so I could try foil powder bags. May have drilled out to much. With the 209s, I have a much larger hole into the chamber, so I can get a decent size hole in the powder bag. As an added benifit, the 209s self eject. Drilled a small hole in the face of the hammer, used lock tight to secure a "bb" in for a firing pin. Works great so far. Still haven't used the foil powder bags, can't find a 1" wurm. Boomer