Harder to pigeon hole early guns. What is your chamber length? The likelyhood of the gun being regulated for 7 to 9 drams is low. I have a 7 dram gun with 3 inch chambers and weighs 13lbs. I also have a # of twelve bore molds I think one is quite large and was sold to me as a 10. The one original roundball mold I have casts just over .740 Post some photos when you can.