User's Manual

However, a weaker main spring would lighten your pump stroke. I find the
CCM® main spring is VERY light and I do not adjust my springs.
I have found that 300 PSI is a great place to start with CCM® markers. You
can use a Pressure Testing Gauge or just start low on the Regulator and turn
it up from there. Perhaps even start at 275 psi and make smaller adjustments
to the regulator to get it to plateau at the highest FPS you can.