Red oring is fine on the striker. I just checked it but I can't get it to recock. When i recock it and dry fire it, it just makes a continuous loud noise and the bolt stays forward. Could it be because I am using a Low Pressure tank?
Try resetting the velocity adjuster to the stock setting. It probably won't fix the problem, but we can try starting fresh. Flush the end cap 1st and turn the velocity adjustment screw 2 1/2 round into the end cap.
It might also be the cup seal. If it is, just call up Azodin and I'm sure they will fix you up.
I didn't see that you said you were using a low pressure tank. That might very well be the problem since that marker was designed to function with C02 which runs around 800 psi. See if you can barrow an HPA tank from some one or rent one from the field and see if that fixes it.
It shouldn't have anything to do with the velocity adjuster in the back, I was just thinking resetting it to stock might help us troubleshoot from all stock. Screwing it in even more would probably make things harder because there is added spring tension not allowing the striker to get caught on the sear. Only screw it in more if you need a higher FPS.