Your're putting the cart before the horse, as you don't go out hunting until you have found the proper choke for your gun that gives a tight pattern to humanely kill the bird with a decent number of pellets in the head/neck area. That is done by experimentation with various shells on paper and is generally with #4, #5, or #6 shot on paper targets out to 40 yards. Each gun is different and until you know what the gun will do you shouldn't be hunting a live bird with it. If you don't have a turkey choke for your shotgun, start out seeing what your full choke will do for a tight pattern and that might be all you need to kill a bird at 30-40 yards.