Ah well at least with American Airgunner his chrony numbers are good. AirgunWebTV had the older CO2 version of the same rifle shooting at 13 FPE's. I can only assume it was a very hot day, but the temperature was never stated which can be critical with CO2.
Anyway, to answer the original question I have noticed he uses a lot of JSB. He did have some H&N in a recent challenge, and uses the GTO Predators when looking for a light pellet to get close to the fps the manufacturer states. Hope that helps.