What kind of accuracy and power are you all gettin from your FX Dreamline?

I picked up a Dreamline classic this winter. I love how it fits me and how it feels. It is accurate with JSB 18 grain but I am very disappointed with the shot count and adjustability. I am getting 850 fps for first mag and then it acts like it is off the reg on the second mag with a consistent poi drop. The reg is at 125 as it came out of the box. I also feel like it should get more than two mags between 230 and 125 bar. I tried to adjust the hammer spring but it doesn’t do much as it pretty much stays at 850ish fps for the full adjustment from full in to full out. I need to call FX and talk to a tech.