My favorite dimensions for actual bird hunting is 1 5/8" X 3". I can use a straighter stock on clays but on unexpected (and unprepared) flushes I shoot with my head up. Maybe strange considering today's fashion but works for me.

Insofar as to "shooting well", that's another matter. I've never climbed above "middling average" but that doesn't bother me and somehow I generally manage enough birds.

When an old man dies a library burns to the ground. (Old African proverb)