Gee whiz, guys. I agree with the above posts to a point. I do 90% of my shooting with a 20 gauge. I don't, however, hunt ducks, and I hunt deer with a rifle. I would have to go with a 12 gauge for those critters. The obvious solution however, is two new guns. A 20 gauge auto for doves and a 12 gauge with two barrels for deer and ducks. An alternate would be to buy a slug barrel for the 20 gauge auto for deer use.
Clemson