I put a detailed response on your blogspot, but try more pellets, especially Hobby and Basic for a lower price and shoot 25 or 30 shots per pellet. Smaller groups can be very misleading.
I always try both rifle and pistol:
For my Tau 7 match and Silhouet; they prefer JSB Rifle match.
My Tau 7 Jr prefers JSB pistol match.
My AlfaProj co2 rifle prefers Finale match pistol..