Yesterday I started to play with a bulk kit for the qb78 in .22 that i have been home tuning for a while now... It was shooting RWS hobbies at 550 fps and it would get about 45 shots with the powerlets... Now mind you i have redone the seals and the transfer port, and played with springs in search of power and bumped it about 45 fps from stock...
After putting it back together i flirted again with a PCP idea, filled it up to 1500 psi and started shooting... It gets 15 shots... about 10 of them at a consistent 640 fps with crosman premiers (14.3) and then it looses about 20 fps per shot... so i stop shooting it when it gets to about 520 fps... So as a PCP hunter it will do the job... it is just LOUD... I am leary of keep filling it pass that, as when i run calculations i came up with 1990 psi as a pressure failing point for the original tube. So i run it at 75% to be safer... I wonder how many shots that would yield...
Well after that stint i emptied it and then filled it from my CO2 tank and ran a string through the chrony... Bulk filled that rifle gives me 36 consistent shots averaging 580 fps with the RWS hobbies. It is also much quieter and puts out 9 FPE in a very accurate and civilized manner. I think i am goint to keep it like that... it will be a great yard gun at that powerlevel.
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