Gunsmithing Thoughts on this firing issue?

[Marksman]

Had a new problem that I haven't encountered before and could use the collective thoughts of the board.

I recently installed a Calvin Elite trigger on a Stiller Predator action. I didn't adjust the trigger at all, just installed it and used it at the weight it was set from the factory. I dry fired a dozen times or so and everything seemed to work fine so I loaded up some rounds and headed to the range.

I fired over a dozen rounds without any problems. Then, I pulled the trigger, heard a "click", but the gun did not fire. I thought it might have been a hang fire so I left the gun alone for 5 minutes. When I went back to the gun to eject the round, when I started lifting up on the bolt the gun FIRED! Must have been a fluke right? I tried dry firing a bunch, working the bolt fast and hard, and everything seemed to be working fine so I went back to shooting. I got through another 5 rounds and then it happened AGAIN. This time I could tell by looking at it that the back of the firing pin assembly had moved forward 1/16" of an inch, but had not completely released. I moved to the side and slowly started lifting the bolt, and sure enough it fired.

Any thoughts?

Is this the Timney/Stiller short sear problem? I would think that because the pin moved forward a short amount after the trigger was pulled it shouldn't be. Is the firing pin binding on something? Is there any lube points I should try?

 

[chipsfan]

Sounds like a sear engagement issue. First thing- stop shooting the rifle. Second- have someone that's knows what they are doing look at it. No sense in getting seriously injured or killed. Having the rifle fire when you are unlocking a bolt is fail city dude.

 

[LRI]

Got your PM.


1. Stop shooting this gun.

2. I would pull the trigger and replace with something else. Just to see if the issue goes away or continues. If you do this, dry fire the piss out of it with a chambered dummy cartridge to try and emulate the conditions as closely as possible. Sounds a bit silly, but were looking for something that we don't know at this point so anything helps.

look at your timney closely. Was anything kinked on the trigger chassis during your installation? Its easy for a trigger pin to roll a burr as it goes through the chassis. Especially with an AL trigger housing. A slight slip can result in the trigger either being pinched or cockeyed as it sits in the well of the action.

-On that note. Triggers that are pinched in receivers are bad ju ju. Custom actions are notorious for trigger wells being too tight. I've seen this more times than I can count. That will create the exact condition your experiencing as we've had it happen here at the shop. Not saying that's what it is, but don't discount it.

Start here and lets attempt to asertain whether its an action issue or a trigger problem.

 

[Marksman]

I'm definitely not shooting this gun for awhile.

I do have some spare triggers of other name brands laying around that I can try as well.

Because I haven't been able to re-create it with dry firing only, and it was after I had shot some rounds through it, I wonder if the action built up some heat and squeezed the trigger a little.

 

[bkw1911]

Those short sears give rem 700 clones all sorts of issues. The 510 with the U sear is the only timney I'll use at this point. I doubt you'd be the only one having this issue do to heat in the action, lots of guys run there guns very hot and a lot of matches are 10 shot strings

 

[sandwarrior]

I'm definitely not shooting this gun for awhile.

I do have some spare triggers of other name brands laying around that I can try as well.

Because I haven't been able to re-create it with dry firing only, and it was after I had shot some rounds through it, I wonder if the action built up some heat and squeezed the trigger a little.

How about make up dummy rounds. Instead of primers, flatten out some used primers and see if you can get one of them to not dent.

The other thing is I would go in with a sharpie, or prussian blue and see what is hitting that shouldn't.

FWIW, to me it sounds like your bolt is out of time to the far end. It fires normally until the one time it catches. Then, the one time it catches, as you pull the bolt throw back through its normal motion, things align and it fires. It's probably in battery, but unexpected firing is never a good thing.

On that note, see if it will fire while lifting the bolt? How high can you lift the bolt and it fires.