Diana Stormrider .22 Air Rifle - Manometer Bleed Value ??

[braidwop]

I recently ordered and installed an Altaros Regulator for my Diana Stormrider Gen 2.  I reinstalled the endcap (My Diana Stormrider has a built-in pressure gauge on the end of the chamber "Manometer" as we as one under the trigger) and replaced the O ring as advised.
I pumped the chamber to 20MPA (using the end Manometer Gauge as well as checking my hand pump pressure reading) as and checked the Regulator was reading 10MPA (100BAR) as expected..
I fired 2 shots (unloaded) to test the gun, then after that a trigger gauge read ZERO (Post Regulator) , while the PCP tank gauge still read 20MPA (200BAR) (Pre-Regulator) ..
I only got 2 shots and when I cock and fire the gun I now get ZERO pressure, but the PCP tank is still FULL..

Now I cannot Remove the Altaros Regulator because the TANK is FULL PRESSURE, and firing the trigger does not produce any air..  so I cant use the gun or even remove the Altaros Regulator as the gun is FULLY PRESSURISED..

Does the Diana Stormrider .22 Air Rifle - Manometer have a Bleed Value   as I need to remove the pressure and cant do it using the trigger...  PLEASE SEE MY PROFILE PIC FOR THE MANOMETER & GRUB SCREW IN QUESTION !!!!!

[Back_Roads]

 OK my example is older non reg version MrodAir branded. Does yours have the gage on the end of the main tube? If so you can slowly loosen that to let air slowly out.