Dick's Sporting goods offers an olive drab gun with three interchangeable barrels, sounds like it would work great for your first rifle/shotgun. I think it's by Rossi, it's called the Trifecta. It has a .223 barrel, a .22 barrel, and a 20 gauge barrel. Last I checked it was less than $300. Of course it will be single shot, but if you're a good shot, you won't need more than one anyway. So whatever you choose, good luck in your future hunting.