FX Help regulator pressure fx panthera compact

what caliber is the gun. Are you wanting to shoot pellets or slugs. With a compact I would be shooting pellets but that is just me.
Why is the reg set so high?
MAybe I am not reading your post correctly, but the gun should fill well past the reg pressure set. It should fill to 250 bar. Then your reg reduces the that bottle pressure to what you want in your plenum. With 180 bar on the reg the stock hammer weight will not be able to open the valve hardly at all.
Help us help you and provide us with more details