Strange Problem

[SchoolU101]

For a short while the gun works the way it's supposed to.

Then the bolt starts to stick but can be temporarily fixed by pushing the bolt back with my finger or sometimes by just smacking the gun (inconvenient to take off the hopper every time).

Soon there after the gun won't fire. Even when you push the bolt back with your finger, it still won't re-cock. The trigger pull still has pressure, but pulling the trigger does not fire the gun.

After leaving the gun alone for a day or so, it works again; then picks up the same cycle.

I've tried all different combinations of carriers, bolt springs and shims. The bolt rides smoothly and takes little force to remove, though it will not slide off on its own. I'm thinking the problem may lie elsewhere. If you have any ideas, however remote, please let me know.

Setup:
ULE Body
RPG Splinter Rail
RPG Chimera Frame
X-Valve w/ ULT
68/4500PSI compressed air

Thank you in advance.

[angrysasquatch]

Definitely sounds like a level 10 problem. Try adjusting only your shims, the problem is that its trying to chuff but the chuff distance i guess is too far.

[rawbutter]

^^^^ What he said. Definitely your LX.

Have you read through the LX Guide?
http://www.automags.org/resource/level10/index.shtml#detailed

[athomas]

It sounds like bolt stick. If the gun won't fire at all, then you need to either increase the operating chamber pressure (higher velocity) or reduce the force required to move the bolt. You reduce the required force by moving to a shorter bolt spring, but that also requires the reduction of the chamber pressure at a given velocity as well. The other culprit is the frictional force caused by using a carrier that is too tight. Using a carrier that is one size larger will allow the bolt to move more freely, allowing the gun to operate effectively with minimal amount of bolt spring/chamber pressure differential force.

Shims only help if the gun chuffs but won't reset. They don't help with resets after a shot has been fired and they don't help if the gun won't fire at all. Shims only adjust the distance that the bolt must travel before it can reset.

[phizz]

A velocity issue maybe? try increasing it.

[SchoolU101]

Definitely sounds like a level 10 problem. Try adjusting only your shims, the problem is that its trying to chuff but the chuff distance i guess is too far.

That's what I thought too. It seemed to get better and better each time I removed a shim, but now I have no shims in there at all and the problem still persists.

The carrier is not too tight. The bolt spring just barely extends beyond the tip of the bolt (not too long). The problem is not simply bolt-stick.

It does seem to work better at higher velocities, but I can't be going out there shooting 320FPS so it doesn't solve the problem; but it may suggest something. What might that mean (runs better at higher pressure)?

Thank you all for your posts. They've been very helpful.

[Coralis]

try taking the bolt out and putting oil directly down the power tube and then firing it . also check to make sure your ball detent isnt screwed in to far and hitting the bolt and lastly check to make sure you dont have the screws holding the grip to the rail and body to tight.