Flyer, this is definitely 'normal'.
I have a Dream Tac Compact .22 cal that I was actually just tuning last night..
I wanted the lowest possible reg pressure possible, while hoping to achieve as close to 880 fps using JSB Hades 16 grain pellets.
After some tweaks, I was seeing consecutive shots at 560ish+ [front dial set to .177/.22]
I was content, and called it good.
Then out of curiosity, I flicked the dial up to max - .25cal, and the fps increase actually brought me right up to 880+ Niiice.
Anyways.. Even though I achieved the # I was hoping for using the max setting..
I'll still be kicking the dial back down to .22 cal - for efficiency sake to save a little bit of air.

Sam -