I bought a predator 314-2 for my Jack Madden cue. The screw is in fact a 3/8 10 just like in your picture. The joint fits almost perfectly, I would guess the difference in diameter between the two is less than .003 of an inch. The predator shaft female threads aren't nearly as snug as the one's John cuts on his shafts though but once it screws down tightly it's really acceptable. Once you use a low deflection shaft it's hard to go back, as nice as my two JM shafts are.