Hi Tinker, no 16 or 20 bore molds, although I might have some next month, just don't know what is available yet on a bunch I am looking at. I think you are right that it is a grease groove, but Paradox bullets used no grease in the groove, the groove was for displaced lead when the heavy rifling was hit at the end of the barrels. I have shot different 8 Bore rifles and 8 Bore paradox guns and with similar weight of charge, bullet and rifle, the paradox guns seem to have lighter recoil. Neat guns, wish I still had one, can't afford one now! Take care!
