Good information, Curator! I used to cast wheelweights for a Marlin 1895 45-70 waaay back in the 70's when they first came out. At that time,the barrels had "micro-groove" rifling, and I never did get good accuracy with pure wheelweight castings for some strange reason. Now that I'm interested in percussion revolvers, and have all these wheelweights, I thought I would use them. When I started this thread, I was thinking about when seating the ball, shaving off the ring of metal insures a good seal in the cylinder. With wheelweights being much harder, I wondered if you would get the same result when seating the ball. All of ya'lls replies have been most helpful.