Trigger not resetting fully when firing

pgb205 · December 3, 2017, 08:58 PM

Just built my first AR15. Function check passes when dry firing, but at the range I went through about 70 rounds and have encountered a problem after each round, which was as follows:

I chamber a round and fire. Rifle picks up the next round and it's now in the chamber. The bolt is in the correct position as well, I am unable to push forward assist at all. The trigger is dead however, and the only way to fire is to nudge the trigger forward until I hear a click. It takes only the slightest of push to have the trigger complete it's reset. After that I can fire just fine.

As I stated before I am unable to re-create this when dry firing. I fire, manually cycle the rifle using the charging handle, and I am able to 'fire' again.

I have attached some pictures of the trigger group; I am unable to see anything amiss myself.

I'd be interested in any ideas that people can give me to work through.

thank you

Mobuck · December 3, 2017, 09:28 PM

Sticking/binding disconnector or improperly assembled disconnector spring.

turtlehead · December 3, 2017, 10:46 PM

Mobuck, does that kind of thing happen if the spring is not fat side down?

ed308 · December 3, 2017, 11:27 PM

Check the springs. The trigger spring looks correct but the hammer spring seems to be under and not on top of the trigger pin. Installing it corrently will increase the tension which will provide more force.

It's easy to make a mistake installing the springs. See the attach video and note the position of the hammer spring on top of the pin that holds the trigger.

https://www.youtube.com/watch?v=z4MA5OqTsWU

Chainsaw. · December 4, 2017, 08:12 AM

Sounds like the trigger spring is in upside down, wont push the trigger all the way forward allowing the disconnecter to...disconnect.

Mobuck · December 4, 2017, 08:20 AM

"Mobuck, does that kind of thing happen if the spring is not fat side down?"

In my experience, yes, it can.

Metal god · December 6, 2017, 01:20 PM

I think ed308 has the correct answer . You can clearly see the right side of the hammer spring is not up on the trigger pin . You can tell because if you look at the second picture , the left side is clearly up and over the trigger pin . Both sides should look the same pretty much . My guess is this may be causing the trigger to drift over to the right and is now rubbing on the lower and causing to much pressure on the trigger and not allowing it to move fully forward .

pgb205 · December 9, 2017, 02:26 PM

I've re-assembled the trigger to make sure that the long legs of the hammer are on top of trigger pin. But the problem was still present.
I've happened upon youtube video where person claimed that new triggers can have burrs which make hammer catch on disconnect. I've did some polishing with a sand-paper and the problem went away--at least after putting 60 rounds at the range today.

thank you all for your help and hopefully my experience helps someone else in the future.

Metal god · December 9, 2017, 02:48 PM

Cool glad you figured it out . With the spring the way it was I don't think anyone was ready to suggest anything else until that was worked out . It's hard to look for other problems when there's a major one looking you in the face .

Just to make sure you only "lightly" sanded with a stone or paper on a block ? The heat treatment on the FCG is very shallow and you can sand right through it if not careful especially the edges if you're just using your finger . The trigger will still work but it should wear faster in that case .

stagpanther · December 9, 2017, 03:21 PM

Is this an adjustable or "run-of-the-mill" non-adjustable mil-spec trigger (hard to tell from the pics)? My WA quess is that between your sear timing and overtravel your trigger is not getting enough "rockering" to allow enough movement to reset--may or may not be just the disconnector alone. Springs look OK to me.

Metal god · December 9, 2017, 03:44 PM

Stag I missed it to on my first look see . The right hammer spring is not up on the trigger like it should be . The OP updated today and fixed that and believes it was actually very rough cut mating surfaces of the FCG .

stagpanther · December 9, 2017, 03:54 PM

Right you are--missed that , though that may also prevent the "rockering" necessary for reset. ; )

Kreyzhorse · December 9, 2017, 09:24 PM

Quote:

Check the springs. The trigger spring looks correct but the hammer spring seems to be under and not on top of the trigger pin. Installing it corrently will increase the tension which will provide more force.

This will do it. +1

December 3, 2017, 11:27 PM	#4
ed308 Senior Member Join Date: November 5, 2016 Location: DFW, TX Posts: 1,147	Check the springs. The trigger spring looks correct but the hammer spring seems to be under and not on top of the trigger pin. Installing it corrently will increase the tension which will provide more force. It's easy to make a mistake installing the springs. See the attach video and note the position of the hammer spring on top of the pin that holds the trigger. https://www.youtube.com/watch?v=z4MA5OqTsWU Last edited by ed308; December 3, 2017 at 11:39 PM.

December 4, 2017, 08:12 AM	#5
Chainsaw. Senior Member Join Date: September 12, 2015 Location: Issaquah WA. Its a dry rain. Posts: 1,774	Sounds like the trigger spring is in upside down, wont push the trigger all the way forward allowing the disconnecter to...disconnect. __________________ Just shoot the damn thing.

December 6, 2017, 01:20 PM	#7
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	I think ed308 has the correct answer . You can clearly see the right side of the hammer spring is not up on the trigger pin . You can tell because if you look at the second picture , the left side is clearly up and over the trigger pin . Both sides should look the same pretty much . My guess is this may be causing the trigger to drift over to the right and is now rubbing on the lower and causing to much pressure on the trigger and not allowing it to move fully forward . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

December 9, 2017, 02:48 PM	#9
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	Cool glad you figured it out . With the spring the way it was I don't think anyone was ready to suggest anything else until that was worked out . It's hard to look for other problems when there's a major one looking you in the face . Just to make sure you only "lightly" sanded with a stone or paper on a block ? The heat treatment on the FCG is very shallow and you can sand right through it if not careful especially the edges if you're just using your finger . The trigger will still work but it should wear faster in that case . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; December 9, 2017 at 03:41 PM.

December 9, 2017, 03:21 PM	#10
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,772	Is this an adjustable or "run-of-the-mill" non-adjustable mil-spec trigger (hard to tell from the pics)? My WA quess is that between your sear timing and overtravel your trigger is not getting enough "rockering" to allow enough movement to reset--may or may not be just the disconnector alone. Springs look OK to me. __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

December 3, 2017, 09:28 PM	#2
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	Sticking/binding disconnector or improperly assembled disconnector spring.

December 3, 2017, 10:46 PM	#3
turtlehead Senior Member Join Date: October 20, 2015 Location: Phoenix, AZ Posts: 1,203	Mobuck, does that kind of thing happen if the spring is not fat side down?

December 4, 2017, 08:20 AM	#6
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"Mobuck, does that kind of thing happen if the spring is not fat side down?" In my experience, yes, it can.

December 9, 2017, 02:26 PM	#8
pgb205 Senior Member Join Date: April 11, 2013 Posts: 104	I've re-assembled the trigger to make sure that the long legs of the hammer are on top of trigger pin. But the problem was still present. I've happened upon youtube video where person claimed that new triggers can have burrs which make hammer catch on disconnect. I've did some polishing with a sand-paper and the problem went away--at least after putting 60 rounds at the range today. thank you all for your help and hopefully my experience helps someone else in the future.

December 9, 2017, 03:44 PM	#11
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	Stag I missed it to on my first look see . The right hammer spring is not up on the trigger like it should be . The OP updated today and fixed that and believes it was actually very rough cut mating surfaces of the FCG . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

December 9, 2017, 03:54 PM	#12
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,772	Right you are--missed that , though that may also prevent the "rockering" necessary for reset. ; ) __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*