Fill Pressure Adjustor on Marauder

[greenairrow888]

There is a way to adjust fill pressure on the marauder, but by turning the adjustment screw how do you know what fill pressure it coincides with? I guess full out is 2000 psi and full in is 3000 psi for example... but how about in between? What about 1/4 either way what should the fill pressure be? The manual states how to adjust the hammer stroke and hammer spring preload either clock or counter clock wise for different fill pressure but again does not state how the user will know what those adjustments will coincide with various fill pressures. And if the adjustments are made for say 2200 psi and you fill to 2500 psi will this damage the air rifle?