Another vote for only using the real stuff, the substitutes will only frustrate you in a side lock cap gun. Hang and mis-fires are all to common. Here is a for instance: A local kid around here tags along with us on hunts. He picked up a used custom sidelock Hawken from one of us. He loves the gun, but he has been a little thick in the head about using regular black powder in the gun. He still had some Pryodex he wanted to use up and despite waht we told him, by God, he was gonna use up that Pryodex before he bought anything else. So, he is out hunting with that gun the other day, gets a small buck in his sites, sets that thing off, the hang fire could be measured with a stop watch. Of course he pulled off target and ends up hitting the buck in the hip. It runs off, forturately he caught a large artery back there and it bled out. I have since given him a can of Goex Express from my supply, told him to pour that damn Pryodex out. He has done so and last report I got from him was the hang fire problem is gone and his groups are a lot tighter - go figure!