I shot a few 20 yard groups with the 11.75 grain .22 GTO Predator, and the accuracy was as good as JSB 15.89s and 18.13s in a BSA Scorpion, Theoben MFR and a Brocock Contour. Velocity was over 100 fps higher due to the lighter weight. I don't know what they are made of, but I am wondering how to remove the metal that will eventually collect. I suspect they are made of tin, but that is just a guess. Shooter's Choice lead remover won't be usable, which is my preferred cleaner for lead pellets.I haven't tested to see if any other cleaner will dissolve the Predator GTO material. Has anyone investigated how to clean a barrel where these lead-free pellets are used ?