RE: turkey hunting
The 20 gauge is by far as good a turkey gun then any 12 out there for the size of the shells. The thing with a 20 is to get a Good choke and something that has the quality in it. This is going to cost some money but it will make a difference.
What I have found with the 20 is that Hevi shot seems to form better patterns then copper loads. By testing the different loads you can turn a 20 yard gun into a 40 yard with No problem. This past season I seen my gun drop birds into the 40+ yards with Hevi 13 #6 and now am going to take the gun to the testing again. I have ordered another 2 chokes to test agaist what I have to see if I can get another combo that will out pattern what I have now. ( I will fill everyone in on the resaults) later this summer.
Every turkey gun I've seen on the range has patterned the best with $60.00 - $100.00 chokes not the 30-40 dollar stuff. The reason is the way the chokes are made. All chokes have tappers in them and the shorter the tapper the cheaper the choke, something to think about..