Any evidence of oldie tyme shootists intentionally using chainfire as a poor-man's shotgun?
I think a poor man would have a shotgun before a revolver. I also think emptying all the shots from your revolver at once would be "counter-productive" to say the least. You could damage your gun, lose some fingers, empty your gun and not hit your target, not to mention wasting your ammunition. There wouldn't be any "tactical advantage" to a chain fire unless your goal was to make your gun lighter or give the bad guy a good laugh while he walks up and shoots you. I think an old school pistolero would be better off trying to accurately put his rounds where they need to go instead of trying to use his revolver in a way it wasn't meant to be used. Pepperbox revolvers had a habit of chain firing and it gave them a terrible reputation. The advent of reliable, non-chain firing revolvers lead to the demise of pepperboxes. I don't think anyone would intentionally try to make a quality revolver malfunction, especially when their life depended on where the bullets went.