Reply To: FX Impact .25 with JSB MkII 33.95gr — what FPS are you getting?
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With 15cc Plenum tube screwed on where the reg gauge connect, I’m getting 910-915fps with 34g @140b as stated on the Waka gauge and verify by 2 other Waka gauge.
with external tube have 2 advantage beside getting more FPS without adjusting anything, at an average of 35-50fps more.
1. the refresh rate to 140b is so much quicker after the shot.
2. I can shoot to 10-15b below reg setting before the speed start to drop.
the final tube will be 1 1/2″ OD 3″ long in black milled from a solid T7 aluminum tested to 300B