Huben GK1 .22 recommended pellets for lower power (UK Sub6)

i have a version 3 GK1 22cal, from Kelly /Krazy , i told him that i have Jsb's 18's, but that i had 9000 Cphp's, kelly set it up to shoot 900 fps with the cphp 14. 's .when i received the pistol , i shot about 3 mags of jsb's, which were a little hard to seat & bent the skirts loading into the stock loading gate, so i switched to the cphp , & no more bent pellets then i [purchased a fast loading gate from Moistone, & every thing is great , the only jams (2) have been my fault, i forgot to close the loader gate, i have shot over1500 pellets (cphp's ) & it is all i will ever use ,$7.47 for 500 at Wm.. PS this is my last airgun purchase, thankfully i am done searching, i found what i was looking for..