>>1943079Depends on the type of hunting. Lots of people here use a 20 for high driven birds, some with incredible success, others less so. It comes down do you being able to shoot or not. Using a 20 isn't some kind of handicap unless you've really reached the limit of range and power which obviously does fettle out before a 12 but that's not an issue for most people. 20's can be great for their size and weight advantage if you're going to walk all day but then it might kick the shit out of you if you're putting big heavy shells through it and you might be just as well using a 12. I don't care what anyone says, recoil is the enemy of good shooting so you need to pick your battles.
I don't know anything about turkey hunting and I have limited experience fighting geese but I gather you might want to stick to 12 for that. If you plan to shoot clays in the off season too a 12 will make you infinitely more competitive if you're trying to keep score.
>tldr; 20 great, no big boom bangs or make shoulder go ochre and birds laugh at u. 12 more versatile, more better, less sexy :D 