Reply To: FX Impact .25 with JSB MkII 33.95gr — what FPS are you getting?
Forums › PCP Airguns › FX Impact .25 with JSB MkII 33.95gr — what FPS are you getting? › Reply To: FX Impact .25 with JSB MkII 33.95gr — what FPS are you getting?
Hey, I had the same issue with not getting anywhere near the 830 fps with the 33,95 gr. JSB MK IIs recommended by “Ted Holdover” with all settings maxed out and a regulator pressure set at 140 bar (read of the gage). I contacted FX in Sweeden and they suggested to set the power wheel at the max position to 15,0 mm (+/- 0,5 mm) as for a .30 cal (my .25 cal was at the factory setting of 18.0 mm). I increased my mozzle velocity conciderably and even with my regulator pressure now set to 125 bar (gage reading) I achieve 924 fps with everything maxed out. The grouping at 50 m is way too bad (5-8 cm but sometimes much less) but I think that it is a barrel issue which. I will soon get a new barrel from FX and I will see if it is ok!