I might point out that the only reason to lube the cylinder is to keep the black powder fouling soft and lube the ball. The only way a chain-fire can happen is if a cap falls off. There is no way flame can get past a ball!
I have a handgun you can come and shoot and I'll prove that statement wrong in 1 shot. (well, actually it will be 6, but you will only pull the trigger once)
Perhaps all guns are different, but if I don't cover the ball in lube, I very reliably get chain fires. Lubing does nothing to affect my caps, so I'm pretty confident that in my gun, lube does more than soften fouling. Although that is a benefit also.


















































