My gunsmith friend re-turns and shortens, etc, barrels all the time. Even flutes them, which I personally think is more or less a waste of time. His retread barrels shoot very well and are not stress relieved. Not saying a barrel CAN'T be ruined, because they can be, but I will say that reprofiling or shortening a tube is not a guaranteed problem by any means.

I've personally put a hacksaw to some Lee-Enfields, a Ruger M77MKII and of course the gunsmith-lopped CZ mentioned. No problems at all, and all have shot very well indeed. My Ruger and CZ are particular favorites and all who handle them and shoot them make me an offer I always refuse.