FX Impact X with FX power plenum, premature velocity plateau.

[guinnster1]

I have a FX Impact X .22 600 mm barrel shooting 25.39 gr JSB Monsters at 880 FPS with the regulator set to 90 bar. When I increase the reg pressure to 140 bar I see no increase in velocity. What is the cause of this early plateau. I know my chrony is working fine. Do I need to change the flow port on the barrel? Any ideas out there?



Max

 

[nervoustrig]

Did you increase the hammer spring tension as well? The higher pressure means the valve is harder to knock open, so it requires a harder strike now.

 

[guinnster1]

That's right! I have the wheel on Max, but didn't adjust the hex screw. Thanks!

 

[guinnster1]

It worked. I'm now at 115 bar shooting 25.39 monsters at 950 ft/s.

 

[nervoustrig]

Very nice! You may want to experiment with slugs at 50fpe in .22 cal, or at least the hybrids if the barrel isn’t suited for slugs.