Trigger Reset on AR

[Shoot'nPlumber]

Hello, just dropped in the trigger group on my 80%'er and the trigger will not reset without completely disengaging. This is my 11th lower build, but only 2nd on an 80%'er, and it is a stag LPK. could it be a defective trigger group or bad machining (was done on a cnc program with a mill) i removed and reinstalled 3 times. Any insight would be great and what would the safety concerns be if it were used like this.

[hermosabeach]

I would set two ARs side by side and watch the sear and hammer engagements and reset

If it is not resetting, I cannot diagnose or start to without seeing the fit between all of the parts.

How heavy or light is the trigger pull?
How long is the current trigger pull vs a normally functioning AR?

[bohoki]

dont know what you mean reset without completely disengaging

you know the standard function test

cycle bolt ,pull trigger, try safety it shouldnt engage it should stop half way
cycle bolt ,pull trigger and hold,cycle bolt, release trigger, pull trigger hammer should fall again and not during the release

[Shoot'nPlumber]

So side by side with an ar that works as should, the trigger pull is the same. Function check issue is as follows...with lower only (no upper installed) push hammer down, pull trigger, hammer goes forward, (with trigger still depressed, drop hammer down,) hammer locks back, then when i slowly release trigger to reset, the hammer goes all the way forward instead of just a 1/8" or so before catching. safety works as should

[bohoki]

So side by side with an ar that works as should, the trigger pull is the same. Function check issue is as follows...with lower only (no upper installed) push hammer down, pull trigger, hammer goes forward, (with trigger still depressed, drop hammer down,) hammer locks back, then when i slowly release trigger to reset, the hammer goes all the way forward instead of just a 1/8" or so before catching. safety works as should

check the spring under the disconnector

also the disconnector could have burs under it or be slightly too big in the front section file the bottom of the front tip a smidge

[markw]

Did you try another LPK in it? Do you have another receiver to compare to? Is the disconnector spring installed upside down?

[edgerly779]

Is the little spring under the disconnector in trigger well. Are the springs in properly?

[uxo2]

Are the springs in properly?

well...are they installed correectly

[Shoot'nPlumber]

Hey everyone, sorry for the delay, I just installed a different trigger group from another stag LPK and that one works just fine, i installed the problem one in another spikes lower and same thing, so it does appear to be a problem with some component of the trigger group. I will examine the dissconnector and springs. Yes it was installed correctly as i eliminated the easiest possibility of install error. Thanks everyone

[edgerly779]

Glad you found problem. I see the grammar nazis are here.

[komishe]

hey i just had the same problem in a recent build.
fixed it by taking a hair of material off the disconnector where it rests on the trigger.
this let the disconnect actually engage with the hammer.
how's that for crap grammar?

[Shoot'nPlumber]

Thanks komishe and bohoki, after very meticulously filing down the bottom of the disconnector, this trigger group is good to go. That saved a lot of potential frustration of attempting to find a replacement without upgrading to a $100+ trigger.