Reply To: Hatsan Bully – Hammer Spring Tension Screw adjustment (7 photos)

Forums PCP Airguns Hatsan Bully – Hammer Spring Tension Screw adjustment (7 photos) Reply To: Hatsan Bully – Hammer Spring Tension Screw adjustment (7 photos)

Link

Rich7777
Participant
Member

On my .25 cal Bully, I ended up backing the Hammer Spring Tension (HST) screw out almost 1/2". I don't know about the power impacts by measuring turns. To set the power where I wanted it, I set my pressure to 3000 psi (just a little above 1/2 the shot pressure range) and started shooting and adjusting the HST screw until I got the FPS where I wanted the top of the shot curve. I was careful to keep the pressure between 2800 and 3000 psi. while I made the adjustments.   

Side note: The HST screw is notched to allow the locking grub screw to seat into one of the notches. If you don't have one of the notches on the HST screw aligned to the locking grub screw, the grub screw won't fully seat. The grub screw will stick out from the side of the action and you won't be able to get the stock back on.