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Discussion Starter #1
I started slowly building an AR-15 a few years ago. I finished it up last year and shot it a few times just to make sure it went bang.

I took it out for it's first real session over the weekend to sight in my Aimpoint, and realized that I have a problem. The trigger does not reset after any of the shots. I have to physically push it forward with my finger. I can hear everything click into place. After I do that it shoots fine. I can also switch it from FIRE to SAFE and hear everything go back into place as well.

Something isn't working right, but I have very little knowledge. I built the lower myself so I might have messed something up when I was putting it together. Can anyone give me some suggestions on where to start or should I just send the lower off to AllStar or someplace to make it right?

Thanks!
 

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Could be that the trigger is too wide for the lower receiver because one of them is out of spec. Could be that you used small pins in a large pin colt lower receiver.

What manufacturer's are the trigger and lower parts?
 

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I also think the trigger could be out of spec so the bushing part could probably be shortened in width.
IT could also be a disconnect that drags on the sear part and there is not enough tension in the spring
to make it over the disconnect sear due to be over sized or a slight out of spec distance
between the trigger pin holes. I have seen both situations before.

Take the lower out and by holding the hammer before it hits the receiver test fire it open. Force the parts to mate
by inducing pressure on the hammer forward. A trigger can be tested very well when open and visually inspected as it works.
Just remember whatever happens when firing same thing could be tracked and debugged in slow motion with the
receiver open so you can see where it is holding up.

It is really hard to determine w/o taking a look but normally should not be an issue difficult to fix
due to the overall simplicity of the AR.
 

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What kind of lower parts kit did you use. Make sure all the springs are in the right spot. Double check to make sure you didnt mix up the sear spring with the bolt catch spring. It should be the small cone shaped spring cone side down
 

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Discussion Starter #6
Thanks for all the quick replies.... The upper, lower and lower parts kit are all CMMG. I'll take a look at things and let everyone know what I find. Other than this, it shoots like a dream and I love it.
 

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I would start by taking the trigger/hammer/springs out of the lower. Take the trigger and drop it into the lower loose, without any springs or anything. See if it binds because it is too wide for the opening in the lower.
 

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I'm placing my money on it being nothing more than the disconnect spring being installed upside down.

°hint if you just dropped it in, its wrong.
The spring is deliberately tapered and needs to be pressed in w/friction fit, not just dropped into the recess whichever way it fits most freely.
Its one of the most common assembly errors actually.

An upside down disconnect spring will bind and not push the trigger back to where it needs to be once the disconnect is engaged, yet the trigger will act fine in all other aspects.

This of course presumes the trigger spring is properly mounted and installed.
 

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*bump* to see if the issue has been resolved, and how
 

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When I did my first build the disconnector spring was a little deceiving.....The spring taper is ever so slight,but you will be able to tell,like the others said it pushes in firmly also make sure you didnt use the bolt catch spring by accident.....And make sure the hammer spring ears are sitting on top of the rear trigger pin,and not underneath it....Check to see if one ear might have went under the pin when you built it.....If that happened it would still line up to get the pin in BUT it would also be enough to bind it up.
 

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Rem-oil?
Why not just pack a dog turd down in there instead?
Quality level is about the same and the poo is radically less expensive.
:D


Small infobit regarding disconnect spring: many, if not all, manufacturers shifted over to a green coating on that spring a while back.
(I wanna say it became the standard over the past 5~10 years, but don't quote me on that)

Other colors are out there but rare. (there is a dark brick red that pops up once in a while for example)
With that in mind, getting a disconnect spring and bolt release detent spring mixed up is almost impossible unless you are colorblind as the bolt release spring is pretty much exclusively silver/uncolored.

Also note that there are some kits with black or some other color trigger and hammer springs, but the disconnect spring will still be green regardless.
 

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Discussion Starter #15 (Edited)
Okay guys... I'm sorry it took so long to update. I just haven't had time to pull things apart. I think that it's failing the function test.

When I pull the trigger to the rear and hold it in place the hammer falls. If I push the hammer back it's catching on the disconnector.

Does this mean that I installed the disconnector spring incorrectly or the trigger spring? If so, what is the easiest way to fix this? It's been quite a while since I put the lower together.

Thanks!
 

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Discussion Starter #16
FIXED.....

It took me a few minutes to figure things out, but the problem was the.....TRIGGER SPRING.

Once I pulled the hammer and trigger out I immediately saw what the problem was. The shoulder of the trigger spring was not under the trigger. It was just laying on top. Therefore the trigger had no tension. You could pull the trigger when it was mounted in the lower and it just flopped around back and forth in there.

Therefore, when the trigger was pulled the hammer would fall and re-seat itself. However the hammer was getting caught on the disconnector because the trigger had no tension to reset itself.

Now when I do the function test I can pull the trigger and hold it. Hammer drops. I push the hammer all the way back. When I release the trigger the hammer resets to it's proper position and does not get caught on the disconnector.

PROBLEM SOLVED. THANKS FOR ALL THE HELP. I just needed to fin the time to pull things apart.
 
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