To break this question down as simply as it can be put, a good bird hunting shotgun is the one that you shoot the best. It does you zero good to have a $3,000 shotgun if you can’t hit the broadside of a barn with it. On the flip side, if you don’t miss with your grandpa’s beat-up pump, then that is the gun I would take to the field. Opportunities are often few and far between, so using the gun that you shoot best trumps all other variables.