Loss of velocity and ULT? or something else...

[TimmyJay]

I filled up to get ready for tomorrow. Chrono'd anywhere from 250-295. I then removed all the shims from the ULT (only had 2 to start with). Chrono'd again and the velocity would drop off 290, 274, 250,240, 190, 165 and would sit in this range. Let the gun sit and it would be back to 280 and drop off in a similar fashion. Then I ran out of paint. Any way the ULT would cause this as it was the only thing I changed.

Thanks