Originally Posted by
SocialD
I tried removing a couple of shims from the ULT, but then it wouldn't fire. Replaced the shims and running away.
Based on this, it probably isn't one of the orings in the regulator part of the valve. If one of the valve regulator orings was at fault, then removing the ULT shims wouldn't stop the air from leaking into the front chamber. This points to a problem at the front section of the valve.
Originally Posted by
SocialD
I then tried a longer bolt spring because it seems like the bolt might not be resetting and then it wouldn't fire. I increased the valve pressure and it would work a little bit.
This marker has been in its current configuration for probably 10 years or so. I understand that the spring could have fatigued or taken a set, but I would think that it would work with a longer spring then. Additionally, I inspected the sear and it looks fine.
The bolt spring does get weakened with use. Its only good for about 50000 cycles. It should be replaced after about 35000 cycles to guarantee that it will cycle and reset properly. I don't see this as a cause of the runaway issue, though. A worn spring usually only causes the gun to cough and take longer to reset.
How does the lip of the bolt look where the sear catches it? Is it nice and sharp, or is it rounded? Does the sear show any wear on the top side?
Also, is your rail bushing in place?
Except for the Automag in front, its usually the man behind the equipment that counts.