Trigger failing to reset

[Kwilm]

I’ve got an SBR with a Timney Calvin Elite that fails to reset after 5-10 rounds of rapid firing. Gun is built with the following components:
SanTan Upper/Lower
Noveske 10.5” barrel with matched bolt FailZero or Rainier Arms full auto bolt carrier (can’t remember which one)
JP silent buffer system with the standard weights
SLR Sentry Adjustable gas block
SilencerCo Saker 556 can

I’ve tried just about every gas block position. Going way over gas and also where the bolt won’t lock open on last round. Tried different mags/ammo.

The gun works great during moderate firing speed but as soon as rate increases the hammer rides back home. Can I be “out running” the trigger? Do I need to adjust the buffer weight? Is there maybe an issie with the bolt carrier? Kind of at a loss right now. Any suggestions would be appreciated.

I do plan on grabbing my other SBR lower with a Geisselle SD3G trigger with a standard h1 buffer/spring to see if I can at least narrow it down.

 

[TMR137]

First off, beautiful rifle. Second, I would not be worried or concerned about the gas system and buffer. Set the gas block as you normally would. I would look more at the trigger itself. I have seen this occur multiple times before, usually I was seeing it on a more consistent basis than you are describing though. First I thought it may be the disconnecter, it wasn’t. Then I swapped trigger and hammer springs. Again no luck. Finally I swapped out the entire trigger group for a milspec set up from another rifle. What I eventually determined was the issue, was actually the hammer was slightly out of spec.

So my suggestion would be to set the gas system up as normal. Swap out the Timney for another complete trigger group that you know works. Hopefully that will isolate the issue for you.

Please keep us posted on the outcome.

 

[Kwilm]

Thanks for the input. You pretty much confirmed what I was thinking should be done. I’ll yank the geissele out and see if that helps. I’ve never had an issue with it on my sbr blackout. It’s pretty much set up the same but with the sd3g trigger standard buffer and spring and caliber. Hopefully that cures it.

 

[whatsupdoc]

Check that the trigger is not making contact with the receiver trigger slot.
The horizontal bar that the vertical trigger pin clamps onto was touching the receiver on mine, had to relieve a little metal for clearance.

 

[Rick7353]

First off, beautiful rifle. Second, I would not be worried or concerned about the gas system and buffer. Set the gas block as you normally would. I would look more at the trigger itself. I have seen this occur multiple times before, usually I was seeing it on a more consistent basis than you are describing though. First I thought it may be the disconnecter, it wasn’t. Then I swapped trigger and hammer springs. Again no luck. Finally I swapped out the entire trigger group for a milspec set up from another rifle. What I eventually determined was the issue, was actually the hammer was slightly out of spec.

So my suggestion would be to set the gas system up as normal. Swap out the Timney for another complete trigger group that you know works. Hopefully that will isolate the issue for you.

Please keep us posted on the outcome.

I would call Timney. THEY SHOULD REPLACE YOUR TRIGGER.

 

[Kwilm]

I would call Timney. THEY SHOULD REPLACE YOUR TRIGGER.

I agree if that’s the problem. I feel pretty certain it is something in the trigger but I want to eliminate everything else that it could possibly be before I call. They have been awesome to deal with in the past so I have no doubt they will. I’ll know pretty quick once I put my geiselle in it.

 

[Kwilm]

So I had a chance to test my sbr with my geisselle and it didn’t do it once out of three mags. I was getting 1-3 fail to resets per mag with the timney. I Talked to them today and they say it sounds like possibly a weak hammer/trigger spring. I’m not sure how to weak of a spring would keep it from locking back but we’ll see. Semding it back Monday so it’s just a waiting game now.

 

[TMR137]

Glad you were able to isolate the issue. I’m sure a Timney will make it right for you.

 

[Kwilm]

Glad you were able to isolate the issue. I’m sure a Timney will make it right for you.

I agree 100%. They’ve always had great customer support when I’ve dealt with them.

 

[grebski]

Timney will 100% take care of you. I had a timney triggers on a rifle where it had a small clearance issue in the chassis and they replaced them right away free of charge. They're a fantastic company.

 

[Timney USA]

We have a 100% lifetime warranty. We can take a look and get it back to you in no time. Give us a jingle... 1866-4Timney and we can chat!

 

[Kwilm]

We have a 100% lifetime warranty. We can take a look and get it back to you in no time. Give us a jingle... 1866-4Timney and we can chat!

You guys have always been awesome to work with. I received an RMA from you guys and it got sent out today. Thanks.

 

[Timney USA]

You guys have always been awesome to work with. I received an RMA from you guys and it got sent out today. Thanks.

Outsdanding! Sorry for the inconvenience but we will get this right!