2011 hammer catching at half cock

[THEMULE]

Just put a new trigger in STI 2011 and it is intermittently catching at half cock.  It is not hammer follow as the gun is still on the bench and has not been shot.  I have tried backing out the over travel screw with no success.  I've tried increasing and decreasing the sear spring pressure to no avail.  I'm at somewhat of a loss as to what to do next.

[SlappyMcTrigger]

If the trigger is hitting the mag catch then it is in effect acting as it’s own over travel block and preventing full sear disengagement. Could need some material taken off the back of the trigger itself. 

[vtecpaoche]

Did you check the pre-travel as well?

[SlappyMcTrigger]

Back the overtravel screw all the way out and try it if you haven’t already. Hold the trigger rearward and pull the hammer back and forth with your ear against the frame. Listen for any clicking noise of the hammer at the engagement point. 

[OrondoShooter]

36 minutes ago, SlappyMcTrigger said:

Back the overtravel screw all the way out and try it if you haven’t already. Hold the trigger rearward and pull the hammer back and forth with your ear against the frame. Listen for any clicking noise of the hammer at the engagement point. 

Do this first, if that clears, then it'll be your sear/disconnect and it's relationship your hammer, where you'll need to fit all three just to get all that done. And your spring sear tinkering is correct. I doubt it's an out-of-spec frame, but wouldn't leave that out. 

[THEMULE]

Thanks for the responses. I’m going to go check for the clicking sound and the mag release clearance now. The gun ran previously with an sti trigger then a modified svi trigger. I’ll let you know what I find.


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[SlappyMcTrigger]

3 minutes ago, THEMULE said:

Thanks for the responses. I’m going to go check for the clicking sound and the mag release clearance now. The gun ran previously with an sti trigger then a modified svi trigger. I’ll let you know what I find.


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 Another way to check this would be to remove the mag catch and see if the issue persists. 

[THEMULE]

 Another way to check this would be to remove the mag catch and see if the issue persists. 

Yep that’s how I checked it. I think I found the issue. I pulled the grip safety and very slowly cycled the assembly. If I pull the trigger just enough to release the hammer it will catch the half cock, with just a slightly more firm pull it misses the half cock position. I believe this would be caused by the sear angle being incorrect and basically just barely sliding off of the hammer engagement as opposed to “breaking” that engagement. Does that seem reasonable ?


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[SlappyMcTrigger]

This very well could be the cause but if you barley pull the trigger then it wouldn’t be abnormal to hit half cock since that is exactly what the half cock notch is supposed to do, catch the hammer if it slips off the full cock shelf. Was there a problem before the new trigger? If not I would suspect the new trigger as the cause unless you also swapped other ignition parts. With the mag catch removed and the trigger pulled does it still fall to half cock?

 

eta: Also check if the trigger or bow is hitting the frame/grip. 

Edited February 18, 2018 by SlappyMcTrigger

[SlappyMcTrigger]

When I fit a new trigger in one of my pistols I had to scallop the rear of the trigger to allow for enough clearance. The trigger could not travel far enough to fully disengage the sear and as a result the hammer would fall to half cock. 

 

[THEMULE]

Again thank you for the help. It seems to be resolved. The back bottom corners of the trigger bow were hitting the frame. A bit of sanding fixed it right up.


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[SlappyMcTrigger]

1 minute ago, THEMULE said:

Again thank you for the help. It seems to be resolved. The back bottom corners of the trigger bow were hitting the frame. A bit of sanding fixed it right up.


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Good deal! I’d recommend loading one round mags (Two if your mags are setup for slide lock) for the first live fire tests in the event you inadvertently made an NFA item. 

[kimberacp]

SlappyMctrigger!    Good tip to know for future reference, along with the fix THEMULE, has mentioned.

[SlappyMcTrigger]

8 minutes ago, kimberacp said:

SlappyMctrigger!    Good tip to know for future reference, along with the fix THEMULE, has mentioned.

Thanks. I’ve had that particular headache and glad I was able to assist. That’s why I love this place, so much good info. I should have joined sooner. 

 

 

On 2/18/2018 at 7:50 PM, SlappyMcTrigger said:

Good deal! I’d recommend loading one round mags (Two if your mags are setup for slide lock) for the first live fire tests in the event you inadvertently made an NFA item. 

Also, don’t know what happened to my font size above. Didn’t mean to yell at anyone for still being setup for slide lock.