i don't see much of an advantage going from a 20 gauge to 12 gauge for a deer gun. All it will do is be more unpleasant to shoot. If your in a state that allows a centerfire rifle for hunting why not get one? remington owns marlin and i think manufactures them now. You should look into a marlin xl7 or xs7. Mossberg also makes a gun in that price range called the 100 atr. If you really want a 12 gauge you could look at a mossberg 500 or a mossberg 835. I'm guessing the remington you own is a 870.