The chain fire begins at the front of the cylinder. I have shot revolvers at night and you would be surprised at how much fire blasts out of between the cylinder and the barrel. Yes , the chain fire was from poor fitting, irregular balls. I began using Crisco over the balls which eliminated the problem but accuracy was lousy. I picked up the correct perfectly round Ball size from a gun show, I believe they were .454 and the accuracy was great. I could actually cut a ring off of the ball when loading.