Tinker,
I have been busy at the shop and with 2 feet of snow that fell at my house this week. No chance yet to do the casting of the choke area. I brought home my Stan Baker bore gauge and the super magnum bore specs out at .733" in both tubes, which is a little tighter than what seems to be the average bore on these old guns. It should be an adventure getting this thing to shoot. I know a few places to hunt whitetails......oh boy could this be fun! I'll try to get the casting done soon.
Steve