Looks like you need to refill it at around shot 30 since it looks like you are off the regulator and notice it stringing down after that. I would also back the power adjuster down to shoot in the 850 to 888fps for better accuracy. Might get more shoots too.
I would also put some vibrators no not vibrators it's called VIBRATITE or use nail polish on the trigger adjustment screw threads and set it to your liking.