I've taken geese with a .410... anyone who says a shotgun is not good enough for a goose or duck doesnt know his business. I often take my full choke, single shot 20 gauge out if i am jumping ponds with geese, so I can nail them in the head. I'd use 3 inch, 2 shot. Tungsten is always better but hey, my brother took a goose with .410, 3 inch ( I think it was 3), 4 shot. If that works, I'm guessin anything will.
It's all in the aim. Go for the head... If you dont get the head, hopefully you'll snap a wing
I just gotta hunt