I have a Remmy 870 "Express" 12 gauge. Composite stock. Been using it for 15 years. It has never seen a decent days treatment in it's life. It lays in the bottom of my kayak in salt water for duck hunting, I bought a hastings slug barrel for it and sit in the stand for hours in the rain. It has been dropped more than once (while empty) It is sitting in my garage right now, uncleaned from yesterday hunt. Every year I paint it with heat paint (used for barbeques and exhaust headers)
That gun has never, EVER had a misfire and has to have fired at least 1,500 rounds out of it.
That being said, if you are stuck on a single shot or just want the versatility, the Rossi barrel combo mentioned before is called the "Trifecta" 20 gauge, .243 and .22. I am probably going to pick one up myself, only I wish it came with a .223 or .308 instead of .243.