Reply To: Fx impact .22 pellet speed
At 4th you are very likely wasting air.
Set the reg to 135bar. Close the valve fully and then slowly open it until 920 fps is reached. It should reach that around the 3rd mark with reg set at 135bar (on gauge) and wheel at Max.
And 120bar on the FX gauge is likely 110bar actual or thereabouts. So setting at 135bar on gauge (125bar actual) would be a good start.