It must be in the connection of bucking and nozzle. The inner barrel might be sitting too far from the nozzle that makes it has loose compression.
If it does sit properly, try to put some teflon tape on to the lip of the bucking. You'll need to be delicate about it so the tape won't mess anything up. The tape would helps tighten the grip of the lip to the nozzle.
If it does sit properly, try to put some teflon tape on to the lip of the bucking. You'll need to be delicate about it so the tape won't mess anything up. The tape would helps tighten the grip of the lip to the nozzle.