I like the "ream it out to .223" idea. Not that there's anything wrong with the .222, per-se. It's just that one of the purposes of the whole shotgun/rifle combo is that it's a reasonably inexpensive way to cover a variety of shooting possibilities. And the .223 is just more readily/cheaply available than .222. If you reload or otherwise don't care about that, the .222 is a perfectly OK round, at least fully equal, ballistically, to the .223.