Ok so I've basically done everything described in Robert Simms little thread and made sure my gun is fine according to him.
The Problem - When pressured up, it has no leak. It is set to 200 PSI (exactly) on the bottom pressure guage. I shot it to check the velocity and it shot SO HARD that it popped the top on my hopper. I recognized this problem to be blow back and lubed the 6 o-rings on my bolt guide, and 2 on the back of my bolt and the front o-ring on my bolt...Then I checked my pressure check valve. Then I made sure I had no lube in my poppet.. to cut this short, I checked everything! It has EXTREMELY BAD blow back every time I shoot, and even busts the paint in the hopper before it's shot! The velocity wasn't even up to 200 fps.. I finally looked into the situation more thoroughly and examined the bolt guide and poppet assembly. My poppet does not use the "spring technology" that I've noticed some do...Could this be the issue? HELP!!!!!!