How did you wreck a shotgun barrel? I mean, there's obviously ways to do it, but it's not that common and they normally don't just wear out.
He's right, though, that shotguns operate at very low pressures. A .410 slug out of a full-length shotgun barrel actually has less energy in it than a .45 Colt bullet. That's why I always tell anyone who's considering getting a Taurus Judge or similar to just buy a basic revolver and use pistol shotshells. A shotshell designed for a pistol can operate at much higher pressure levels. If a .410 is less powerful than .45 Colt even out of a full-length barrel, how anemic do you think it will be out of a pistol-length barrel?
