This is my first year waterfowling. I was just givin a Bernardeli, One of the finest shotguns of Italy. Its a 20 guage and a great one at that, I've been using size 4 express shots and i've brought down 4 mallards, a widgeon, a teal and a pintail so far and one goose but the goose was brough down with luck alone, the field was full and we snuck up on them i only broke its wing and then several shots later i still had to cut its throat to put him down. size 4 i would suggest for teals or pintails, and so i've now started using size 2 for mallards and i can honnestly say its making a huge difference in my shots. Are there Double B's in 20 gauges, havent seen any yet?