FX Impact m4

I'd start with some plain JSB pellets, as they are recommended by FX. Then you can evaluate how those work and see if you want to try anything else. Recently I've been shooting well with JTS, but I haven't tried those in my M4 yet.
Are you shooting a .30? I don't know much about one. What about your m4? How you like it
 
Ok guys I made my mind up im ordering an Impact m4 600 mm in .30 cal what are some good pellets to start out with. Thanks. I have never owned a .30 cal pcp alot of .25 and .22 but never a fx or .30 can't wate lol
There aren’t really a lot to choose from. Try on the 44gr first and you probably won’t have to look any further. JSB and FX are the same. Compare to the AEA.