Reply To: what is the Crown .22 prefer FPS with JSB 18.1 gr?

Forums PCP Airguns what is the Crown .22 prefer FPS with JSB 18.1 gr? Reply To: what is the Crown .22 prefer FPS with JSB 18.1 gr?



I played around with the speeds I shot the 18.1 JSB’s at for quite a while. After having great accuracy shooting then at 920 from my Airwolf MCT, I tuned my WAR Flex to shoot them at 915 with phenomenal accuracy. I had several 5-shot groups at or under 1” at 100 yards at this speed. I didn’t notice any weird spiraling or accuracy degeneration until I hit almost 960-970. I don’t do anything special to my pellets and don’t sort them. I always used to stick  to the 850-880 range until recently, and I won’t go back until I see negative effects. The ST X barre on the FX guns may not play so nice with the diablo pellets at those speeds, but that might be able to be remedied with the different twist liners they claim to be releasing soon. As mentioned above, I would get your range set up on a nice calm day and keep turning the speed up until you see some issue pop up. For me it was very evident.  I went from 1” – 1.5” groups consistently to 4” groups within a matter of 10 FPS. Find that threshold and de tune a bit to give you some wiggle room. I had my best luck tuning at 100 yards because I could actually observe the pellet flight through the scope. If you can’t swing a 100 yards, 50 yards would be the minimum I would tune at. 


When i I had my crown, I had it shooting the 18.1’s at 880 with pretty good groups at 50. I didn’t have any spiraling or pellet destabilization.