Exactly my point. If the pressure is over 200psi, air will vent from the silver disk underneath. Its a safety measure so no damage is done to the mini.that hole is there to make it easier to take the bottle off and relieve the air pressure between the bottle and the reg. its sounds like it the oring on the bottle needs replacing or tje bottle needs to be in a little tighter. in terms of reg pressure never exceed 200PSI as it will wreck the gun