Does anyone know how much a 12.9mm Revo shaft should weigh or does Predator have a spec for weight? I have two Revo Shafts, both 12.9mm. One of them weighs 3.6 ounces and the other weighs 4.1. Thats a huge variation IMO. So much that the shafts are not really interchangeable on my cue. It completely changes the cue balance.