I have charts showing this difference in Easern & Western buck but off hand don't recall for sure where. As Researcher has already answered will not bother. Note also that back around the turn of century (1800/1900) different towers used different specs for their sizes. Was fairly common to specify shot by number as well as by tower, as Fred Kimble once mentioned using St Louis 3's for duck in his 6ga ML. Eventually Tatum/Tathum Bros NY (have seen spelled both ways) was accepted as standard & is still used today.
