Hatsan Hatasan Blitz 777

In case of the 777 there is a flat screw on the opposite side of the bottle pressure manometer.
Slowly turn it counter clockwise to release the pressure from the 700cc bottle.

Note: allow the air to escape slowly and do not remove the entire screw. Also pull back the charging bolt to cock the rifle when recharging the bottle (slowly) Decock the rifle when you are done.

Never leave the trigger spring cocked for long periods of time to prevent spring fatiqe