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5/1/2025 4:29:50 PM EDT
[Last Edit: hidaro][Edited]
I just switched my nice larue trigger out for a mil-spec trigger group. I'm noticing that the trigger is binding. The trigger resets and functions normally, but this is strange as I've never had any trigger do this.

What should I look for?

5/1/2025 9:03:18 PM EDT
[#1]
Are you positive the springs are installed properly ?
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.

________________________________

TOGC,IADC
5/1/2025 11:22:14 PM EDT
[Last Edit: sully][Edited] [#2]
From what it looks like in the video, you are having to push the trigger forward to get it to reset to what is called hammer/trigger sear engagement, and this will then allow you to press the trigger to the rear and get the hammer to release and go forward and fire.  Is this correct?  If so, as already mentioned are the springs installed correctly, specifically the trigger reset spring?




Next I would install just the trigger by itself and see if it freely moves up/down inside the receiver, or does it bind.  Check the same with the hammer.  I have seen where the trigger and/or hammer is too wide where the pin comes through, and it would rub inside the receiver and bind things.  Along this same line is to check to see if the hammer or trigger is sticking on the hammer/trigger pin, if this is the case then try and figure out if it is the pin or pin hole where the issue is at.  A simple fix for this is to carefully stone the rubbing area, until you get it to move freely.

Another possibility is the hammer is getting bound up on the disconnector.  The disconnectors a lot of times are a stamped part (many stamped right to left).  This stamping can leave unevenness or burrs on the disconnector, if this is the case it can also be carefully stoned, being careful not to take off too much material which will cause things to slip and slam fire.

CY6
Greg Sullivan "Sully"
WeaponsArmorer
SLR15 Rifles
Defensive Edge Training
(763) 712-0123
5/2/2025 12:15:08 AM EDT
[#3]
The video is just demonstrating the trigger is rough and getting "bound up" before the break.

The trigger functions just fine, resets properly. I tried polishing the sear engagement surfaces and it didn't improve it.

I'll do another polishing pass and ensure my springs are 100% correct but I feel if they weren't, the trigger and firearm wouldn't be functional.
5/2/2025 11:47:43 AM EDT
[#4]
Try removing just the safety and just the disconnector, one at a time and seeing if it changes anything.  Could point to some binding happening with the trigger and one of those parts.
5/2/2025 3:01:14 PM EDT
[Last Edit: Dano523][Edited] [#5]
Easy solve, and start by removing the entire FCG, with maybe leaving the selector in play.

Now before you install anything, make sure to lube all the FCP parts with CLP, including the channels and pins, and check the side C channel in the trigger for burs, the disco channel for burs and may want to check the disco and hammer hook for burs as well.



Now start by just installing the lubed trigger and disco into the lower receiver.  
At the same time, make sure sides of trigger is no so wide that each side is binding up side walls of the lower receiver cavity walls, and that the U slot in the selector is not binding up on the side walls of the tail sides of trigger.  
If all that is good, trigger is moving freely in lower receiver, them installed lubed  hammer channel and pin for  in the lower receiver, and make sure that spring legs of hammer go forward down, then over trigger pin.



https://i.imgur.com/aMIboK7.jpg

As for stock FCG having a touch of trigger pull creep before hammer release, kind of normal before any FCG smithing, but when you come off the trigger, the angle between the hammer sear, and front trigger sear, is angled to force the hammer to push the trigger back, so long as hammer is not binding up, or edge of trigger sear/hammer sear bur city instead.

If after the above, and still running into the same problem, then need photos of the hammer sear for trigger, and front trigger sear to see if a bur mess, or less then ideal finish on them instead.
Posted By PlaymoreMinds:

'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...

<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
5/17/2025 8:06:08 AM EDT
[#6]
Is the width at the top of the trigger the same as the previously correctly functioning Larue trigger?

In another word is the top of the trigger slightly binding on the trigger opening in the lower.

I had this happen once with a trigger I cannot remember the brand and spikes lower.

A file solved the issue.
5/17/2025 8:47:18 AM EDT
[#7]
I think the real question is why change a mbt to a mil spec?
5/17/2025 8:51:46 AM EDT
[#8]
Quote History
Originally Posted By nyrifle:
Is the width at the top of the trigger the same as the previously correctly functioning Larue trigger?

In another word is the top of the trigger slightly binding on the trigger opening in the lower.

I had this happen once with a trigger I cannot remember the brand and spikes lower.

A file solved the issue.
View Quote


Yup. I had a Peace Geeks lower where the trigger opening wasn’t cut correctly, and had to be filed out to allow a trigger to function.
5/17/2025 6:52:52 PM EDT
[#9]
ALG made by Geissele is my go to trigger for ARs.  Smooth, clean, single stage. Never a problem!

https://www.youtube.com/watch?v=QPWe4-Dv-rk

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