Well, Pecatonica River has a blunderbuss barrel in .75 caliber 20 inches long, oct/round 1 1/8 inch at the breech, with plug installed for $215. It has a nice muzzle swell with a ring behind it, looks good. they have the complete kit for $675, which includes the barrel and a fully precarved stock including a Queen Anne lock, etc. Ph# 815-968 1995.