It’s more than likely coming out your barrel. Take the shroud off your barrel and zip tie/tape a water balloon or a finger cut off a latex glove onto your barrel liner. Make sure your guns pellet probe is seated(or gun is uncocked).
Watch for the balloon to fill. If it does, it’s your valve seat. Also, you have a vent hole close by your regulator gage. Place a piece of electrical tape on top of that hole. If it develops an “outsie” bubble that means your reg is leaking.
These are the two main areas for that type of fx gun to leak at.
Meanwhile, go to fx.com, look up your parts diagram under the support section, and get your guns o rings ordered thru oringsandmore.com. Fx provides the sizes, DURO rating, and o ring type for all their guns
