I have read stories of old farmers using a 45 colt round in a 410 shotgun to put down an animal. I believe they were using cowboy type loads, BP and all lead bullets. Soft lead will swag and go down the barrel. The question is why. They did for necessity, not for fun. I personally have fired 45 ACP rounds with a hand load of trail boss and a 430, all lead, round ball, Patched to hold it in the case, out of of my 410 Tamer. Fired and went down range. No practical purpose, just an experiment. I used a thin rubber O-Ring to hold the shells up against the rim cut. Worked fine. Heck my son put a 22lr in my 17 HMR and fired it down range. Hit the target at 50y. He was seriously admonished and retrained. It did fire with no issues. Again all lead. There is just no reason to try it.