Classic 68 Bolt stick - cycling problem

[Marcus Eriksson]

Hi,

This is my setup, Classic 68 Mag. back part of the valve assembly and the bolt is from ANS, i've got a huge expansion chamber and a pro-team trigger frame.

my problem is, when I fire to fast, it seems like the bolt doesnt have the force to move forward after a couple of shots. its starts to cycle slower with each shot until it stop in the forward position. this happens if I fire 4-5 shots really fast. Could it be that i short stroke? also, sometimes when the bolt stick forward it leeks from the bolt, but it stops when I press the bolt back.

If I fire slow everything seems to be working fine, all the O-rings look ok but i've changed the regulator seat and the o-rings in the on/off. I''ve tried to gas up without the expansion chamber, but that only made it worse.

Anybody got an idea of what it could be, or is it just short stroking?

regards

Marcus

[Asym]

Sounds like your getting liquid Co2 in the valve. The expansion is helping but if you remove it it gets worse with the same simptoms. How is your Co2 bottle mounted? is it into a standard ASA adapter mounted horizontaly on the bottom of the trigger frame? If so and you you a tank without an anti-siphon tube your feeding liquid Co2 straight into the expansion which helps but under rapid fire will not keep up.

If you are using Co2 best things to do are keep that same setup and install some anti-siphon tubes in the tank. Or get a good regulator that will handle Co2. Or go with a remote line to the tank to give yourself a little more room for the Co2 to expand. The remote or anti-siphon are fairly inexpensive. The regulators are a little more expensive but better at keeping liquid out if they will handle Co2 well, I've used Palmers stabilizers with good luck for over 6 years. If you use a regulator make sure it will handle Co2 and isn't a low pressure reg that won't go above 500 PSI.

[Spacemanvic]

I ran a CO2 remote on my mag for at least 3-4 years. I had an expansion chamber on the remote, and another on a drop down on the mag. Never had a problem with liquid.

[BigEvil]

I ran a CO2 remote on my mag for at least 3-4 years. I had an expansion chamber on the remote, and another on a drop down on the mag. Never had a problem with liquid.

I had a similar set up. It would work all year, even in the dead of winter. I dont miss those remote lines one bit.

[Maggot6]

I'm sure you've oiled it....

[Scott Hudnall]

I concur with the above opinions on CO2, exp chambers, remotes, etc.

If you are experiencing true "bolt stick" you may have simply over-tightened the front grip frame screw and field strip screw, causing a slight "bow" in the 'mag body, throwing tolerance out of whack "just enough" to cause bolt stick or drag on the bolt. try loosening the front grip screw just a bit and see if that helps. don't leave it "loose", just don't crank down on it to tighten it, just snug it good. Same with the field strip screw in the back of the frame.

[Marcus Eriksson]

..

well I have been very careful not to tighten the grip frame screws to much, because if I do, then the barrel is really hard to get in. But I have lately have som problems getting the back grip frame screw in without having to "wiggle" it in into the regulator assembly. Do I doubt that it has anything to do with the shootdown.

The weird thing is if I keep on shooting steady about 1b per sec, nothings happens, its only when I increase the rate of fire. Could it be the trigger rod that is not set properly?

and for the first reply, yes the tank is mounted horisontally under the frame wia a rail and asa.

thanks for your replys...

//Marcus