I bought an FX Wildcat Mk1 a few months back. It stacks CPHP's at 20-25 yds at 930fps. I haven't tried anything else in it. I doubt that the new to me Prophet II is going to like them as it sits. It's tuned to shoot JSB 25.4gr's at 960FPS. I'm sure the CPHP's will be super-sonic. LOL I am curious to see how they shoot if it's tuned down around 880-920fps.