I have several 28 gauge shotguns. A little drilling with 28 gauge tubes on top with 6.5x57R for a rifle on the bottom would be a trim and very handy gun. I have found the 28 gauge to be a very good shotgun choice for most of my wing shooting. I have used it on pheasant, quail and dove. I even took one to Africa and shot a spur wing goose with it (It did take 2 shots on the goose).
Robert