heavy-impact,
I've done it a couple of times to turn poor-shooting "old" .22 STX 700mm liners into 600mm liners. I had a friend with a metal shop cut them using a lathe and recrown the new muzzle. One shot pellets much better than the old 700mm liner and shot slugs (almost) as good as a new 600mm Superior liner. The other 600mm was not as consistent with pellets as the first one(I think because QC was not as tight on the "old" STX liners and almost every one was different and shot differently), but still shot (some) slugs well. I wanted another 380mm liner, so I chopped that one down again from 600mm to a 380mm liner and it performs (nearly) as good with pellets and slugs as my 380mm Superiors. They do get way dirtier quicker than the new Superior liners though.
Making lemonade out of lemons because those old 700mm STX liners were useless to me and nobody wanted them after the Superior liners started coming out.