[skeet]

GOB..20 ga bore size is about .615..but the round ball for the gauge will be under .590..maybe as small as .570. Punkin ball loads are usually roll crimped and there was usually a card wad with the center cut out to fit over the round ball. I also have a recollection there was a cutout card under the ball too. I measured one of them once and if memory serves me right the card wad was approx. a .200 size in 12 ga. Never measured a 20..a 28 card with hole was .100 I think. Punkin balls were loaded in 10 12 20 28 and some say 410..but I have never seen a 410 punkin ball... have seen some 410 multiple round ball loads. But for deer etc it would be anemic. Even the 20 would be a short range proposition at best