I was deciding on barrel kits for my FX Impact and ended up buying an Uragan King .30, Oops task failed successfully

Those little Kings in .30 cal make some nice power. Right out of the box and not broken in yet mine was making 91 FPE at the muzzle with heavier pellets, all while being backyard friendly without any additional moderation. Enjoy your new gun!
Uragan King .30
How much does shot count drop if you only fill to 250bar? Any other effects of a lower fill pressure?