On/Off Pin Not Fully Resetting.

[Toestr]

Occasionally my on/off pin won't reset fully as evidenced by the trigger rod staying further back. Picture 1 is the distance at which the trigger rod usually sits (credit card width/ 1/32") and picture 2 is how it sometimes stays (about 1/16"). Sometimes the rod will move forward gradually after releasing the trigger. It always comes forward enough to catch the bolt though.

Any thoughts? I've tried oiling the Teflon orings and it seemed to help for a bit but it's back to this after about 300rds. I've adjusted the trigger rod a bit since it was too far out when I got it. With a credit card gap between it and the trigger it doesn't fully depress the on/off pin to get the valve out. The on/off assembly is all stock AGD.

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[nak81783]

Is the bolt fully resetting? If not, is your bolt spring about 1/8” past the nose of the bolt when out of the marker?

Change the two Teflon o-rings. If you’re using HPA, use urethane 90 durometer instead of Teflon. Only need Teflon for CO2.

I machined a hole in the bottom of the trigger frame to depress the on/off pin for easier disassembly. The newer frames have this feature.

Edit 09-Aug-2023: “disassembly” was “assembly”

[Toestr]

Yes the bolt is fully resetting, my concern is that it's might not recharge the chamber as quickly and the different trigger feel would make it more difficult to keep a rhythm. The bolt spring is good.

I think the point of the Teflon orings is to keep the bolt depression smooth. Urethane is meant for high wear/CO2 applications.

I've also drilled a hole in the frame to stick an Allen key to depress the sear.

[superman]

The white teflon orings are used for the classic mags because of co2. you can use urethane orings as a direct replacement in the on/off, especially if your using hpa.
I find that on the cf frames i have to run the sear rod a bit further out as they have more flex and less travel than other frames.

Are you positive your bolt spring is not the issue? have you tried stretching it and seeing if it is temporarily resolved?

[Toestr]

I don't think it's the bolt spring. It's maybe 3 years with minimal use and I take it out for storage. Besides the bolt doesn't have any issues with latching. I have a spring in the powertube instead of a spacer. I don't know if that's relevant.

[nak81783]

In my opinion, and if your funds allow, you should get a Level 10. They’re just easier on paint. Chops aren’t as much of an issue with today’s force feed hoppers (if you’re using one), but a Level 10 does still prevent breaks with the slower initial bolt acceleration.

If you want to stick with Level 7, get a power tube spacer kit, and use the longest spacer that doesn’t leak when the marker is aired up and at rest. The spring may be causing bolt stick.

[Toestr]

I'm happy with Level 7 for the time being. It's always been the plan to upgrade this to the spacer kit, I just never had the immediate need to.

[nak81783]

Also, what velocity are you at?

[Toestr]

280 with plenty of adjustment left in both directions.

[Brokeass_baller]

Is your on off top upside-down?

[Toestr]

No, it's one of the symmetrical ones.

[Toestr]

The issue is confirmed to be bolt stick. I pushed back on the bolt when this was happening and the trigger rod came fully forward. The fact that it was latching and recharging the chamber threw me off.

Thank you everyone for the suggestions.

[Toestr]

I bought a set of powertube spacers and it doesn't alleviate the issue. Works fine with an old fat style sear and a powertube spring (just haven't tried the spacers with the fat sear, but I suspect they will work fine). Is this just something that will need to wear in?

[nak81783]

Have you tried another bolt spring? I know you said it’s good, but at this point, you should try a different one.

In the image below, red bolt is hung up on orange sear ramp. Trigger may feel like it’s pressurized, but the on/off pin hasn’t lowered past the on/off top o-ring yet. The trigger pressure you feel is the on/off pin against the regulated input pressure trying to get to the dump chamber. Without pressure in the dump chamber, the bolt won’t go forward. Without a strong enough spring, the bolt won’t go back any further to let the on/off open.

[Toestr]

I believe I tried a new spring with it originally with the powertube spring and it didn't make a difference. I'll try again with a spacer and see. The issue I'm having is that it doesn't *fully* reset. The sear will always latch and the dump chamber will always fill it's just sometimes the sear doesn't fully engage with the bolt and the seat rod will sit maybe 1/16" further back than usual. It will fire like this, but it's harder to keep a rhythm and short stroking is easier. When it's like this if I push back on the bolt the sear will seat fully and the rod will go forward where it should be.

[nak81783]

What’s the velocity over the chrono, both for a normal shot and a slow recharge shot? I realize you said 280 earlier, but I want to clarify between a normal shot and a slow recharge shot. Do you hear and/or feel a difference in the shots? I’m wondering if something in the regulator isn’t working right.

Did you ever change the on/off o-rings? This was discussed early in the thread, but I don’t see where you actually changed them. Either of the two that seal on the OD of the on/off pin can get sticky, causing slow recharge.