Trigger out running bolt?

[Dad]

I shot my 1st PCC club match yesterday and I have an issue.

I bought a simple PSA 9mm PCC, added a Timney 3lb trigger and have shot a couple hundred rounds before going to my 1st match.

During the match I had several occasions while shooting I would pull the trigger and nothing happened, pull again and it would fire.

I did have to rack bolt just pull again and it would fire.

 

Any idea where to start looking for this issue?

 

Thanks

[StealthyBlagga]

When it happens, instead of racking the bolt, simply move the safety to SAFE then back to FIRE (or try pushing the trigger forward with your finger). If the trigger then functions as normal, it means the trigger is not returning all the way forwards when released. This phenomenon happens with blowback guns (and sometimes suppressed guns) when burnt powder residue coats the trigger parts and thus increases friction. If the above experiment confirms the issue, I'd send it back to Timney with an explanation and have them fix it. This is not a user-fixable problem.

 

Is it a PCC-specific Timney trigger, or their regular AR15 trigger? Regular AR15 triggers can be problematic with PCCs, so Timney sells a PCC version.

Edited September 16, 2019 by StealthyBlagga

[Dad]

It is just an AR Timney.

 

When this happens all I have to do is pull the trigger again, nothing else and it will fire.

 

 

[MemphisMechanic]

How far does your bolt have to move to the rear before the hammer cocks? Hammer height / bolt height vary with various 9mm parts manufacturers and trigger makers.

 

If the bolt doesn’t cock the hammer in the first inch or so of it’s travel you may run into resetting issues: a friend has a similar issue when his build didn’t reset the trigger until nearly at the rear. There wasn’t enough time for the disconnector to consistently catch the hammer.

 

Sometimes, it would fail to reset.

 

Edited September 16, 2019 by MemphisMechanic

[HoMiE]

47 minutes ago, StealthyBlagga said:

Is it a PCC-specific Timney trigger, or their regular AR-15 trigger? Regular AR15 triggers can be problematic with PCCs, so Timney sells a PCC version.

It seems the AR versions of trigger don’t have nearly enough engagement of the disconnector so the sear doesn’t catch on hammer hooks. 

[RaylanGivens]

@Dad  What bolt are you using?

 

 

[StealthyBlagga]

3 hours ago, Dad said:

It is just an AR Timney.

 

When this happens all I have to do is pull the trigger again, nothing else and it will fire.

 

 

 

Could still be the trigger is not resetting, and your pulling it the first time helped it reset. If its only happening during matches, it could just be trigger freeze. Or it could be something inherent to the trigger. I'd suggest reaching out to Timney to explain your situation - they are good people and very helpful.

[Dad]

Thanks Guys

 

[chevrofreak]

Adjustment screws set for a short pull and reset?   Too short and dirt and heat, or even an off-axis pull can make an over-limited trigger not work.