I ordered an OB FUSION for my JOSS from Seyberts. . The shaft wont screw onto my main shooting cue but will fill another JOSS butt and JOSS Thor Hammer butt. All my standard maple shafts from JOSS will fit all butts to include my main cue. I have asked many people and with cues in hand and everyone is stumped. All butts and shafts have the same joint 5/16x14. Any ideas?