So, I've read pros and cons of tumbling loaded rounds to clean them. I cleaned 4 m1 carbine rounds, circa 1940s Austrian manufacture with Fritz by hand with the cartridge rim chucked in a drill.took a long time. The other 418 went into the tumbler 150 at a time with 2.5 lbs media and 2.5 Oz. Fritz for 1 hour. Some look brand new but others are still discolored but clean and smooth. That's what I was after. No explosion! Would there have been a better way?