Probably the most "out there" I've seen ... I gave a friend a shot out take off Rem 700 LVSF .22-250 barrel. He did a "bit"
of work and adapted it to a 10/22 action. It shot well.
I saw one (IMHO) bad combination. Someone, either my grandfather or one of his friends, had fitted a Winchester 71 barrel (.348) to a Win 1886 action and was refinishing the metal and wood. I doubt they had the know how to harden steel .. nor any certainty the steel was good enough to begin with .. so I suspect it was probably a disaster waiting to happen.