I just measured the bore.... Sure is good to be back in the swamp with my tools.
Bore is 3.75" at the muzzle so its a 6 pounder.
I do not intend to shoot this tube, its iron, its old and IMO the chance of destroying something old and cool is too great. Same reason I haven't removed the silver paint yet, I want to do no harm.
Someday I'll post about the previous owners....
Mike