I have quite a bit of experience with .20 at legal limit and FAC power levels. Although it is true to say that there aren't many pellet types to choose from you would be exceptionally unlucky not to find one to suit your gun. My starting point is to use FTT at legal limit and JSB 13.7 grain at FAC levels. That usually works although things can work out perversely as my .20 Rapid legal limit definitely prefers JSB. OK they are heavier but that is easy to use-you just aim higher!! Whereas the FTT would requitre 2 mildots of elevation at 55 yards on my club range, the JSB needs 3. The advantage with the heavier pellet is that it is less affected by wind. My .20 springers prefer FTT. At FAC levels (a Rapid at 24 ft lb) I actually use Crosman Premier for no better reason than I inherited a load of them.The JSB is just as good.