As far as "ringing" a 12 ga. shell goes, I have also heard of it being done, but never tried it myself. Can you imagine the added recoil or worse if it was fired in a super tight full choked gun? I personally wouldn't want to be behind it, or anywhere around it. I remember taking the front bead out of an old single-shot 12 ga. extra full choke with a "punkin ball" years ago, when I was just a kid. It not only took out the bead, bot split the barrel from the bead to the end of the muzzle. That was the end of that kind of foolishness for me. Kicked like a S.O.B. as I remember it, too.