I look at as a set of scales, if you tighten the spring your putting more into one side, so the other side must go higher to balance it out. Only when it's balanced does the reg close and set the pressure. When you shoot the marker that side of the scales go light, so the reg opens to let air in until the sides balance again.
No idea which way the ion reg adjusts though...
No idea which way the ion reg adjusts though...