So you’re playing in league or a tournament and every time you throw your darts you are tightening your dart shafts as you walk back. Sound familiar? The simple solution is to use Rubber O-Rings. They work like a washer between the thread of the metal dart shaft and the dart barrel. When you thread metal into metal, it can’t “grip” itself. So when using a metal or alloy dart shaft, you will need to use Rubber O-Rings.