AR 15 not setting the trigger

[Rocketrob]

I have a complete upper on an 80% lower build and it is cycling but not cocking the trigger. It loads the next round but I have to pull the charging handle back an inch or so until I hear the click of the trigger setting.
Anyone have any ideas what is going on?
Thanks,

[pluke the 2]

Do you have your disconnect spring installed?

[dessertfirst]

Or installed upside down?

[crs gns n thngs]

What trigger group is it.

[CouchOperator]

Pics

[Rocketrob]

Trigger group is a Geislie and will try to check spring but thought it was correct.
Will try to get some photos up.

[mej16489]

Trigger group is a Geislie and will try to check spring but thought it was correct.
Will try to get some photos up.

Did you perform a trigger group function check? What are the results?

http://www.opticsplanet.com/howto/how-to-clean-ar15-inspection-and-function-check.html

[sintax]

i've also seen this problem where the grip screw is causing issues with the trigger pack. A washer or two on the grip screw usually fixes this issue.

[Exdc]

If it never allowed you to fire two rounds consecutively, you have a sexy bolt action. No need for CA compliance features* ;D (*I AM NOT A LAWYER)

In all seriousness, what buffer/spring do you have?


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[Rocketrob]

< 10. Inspection and Function Check
Page
Back
10. Inspection and Function Check
Next
Inspect weapon from muzzle to buttstock looking for loose parts. Key areas to check are the pistol grip, buttstock, and muzzle device.

After clearing your firearm, this is the second most important step in cleaning your AR15. I always do a functions check when I reassemble any firearm. This is the only way to insure it is assembled properly, and it is a good way to check for worn parts. Fortunately, the AR15 really cannot be assembled incorrectly. If you got it together, 99% of the time your AR15 will pass the functions check.

Make sure the rifle is clear.
Place the selector switch on fire and squeeze and hold down the trigger. You should hear the hammer striking the firing pin.
While still holding the trigger, pull the charging handle fully to the rear and let go to reset the hammer.
Release the trigger. You should hear a mechanical click. This is the disconnector releasing the hammer onto the trigger. If you do not hear a click, or the hammer completely falls onto the firing pin, you have a worn disconnector, hammer, or trigger and they need to be replaced.
Place the selector switch on safe and try to pull the trigger. The hammer should not fall. If it does there is a problem with your selector switch and/or trigger. >

The first time it made the disconnector noise then every other time no joy. So sounds like the disconnector is not releasing the hammer. Some photos attached - I think the spring is right? Not sure about buffer and spring but thinking it was a Anderson set.

Thanks for the help!

[anonymous308]

In all seriousness, what buffer/spring do you have?


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Curious as well

[Ron Swanson]

Mine did that when I had a spring in backwards. Can't remember which one now though.

[mej16489]

Make sure the rifle is clear.
Place the selector switch on fire and squeeze and hold down the trigger. You should hear the hammer striking the firing pin.
While still holding the trigger, pull the charging handle fully to the rear and let go to reset the hammer.
Release the trigger. You should hear a mechanical click. This is the disconnector releasing the hammer onto the trigger. If you do not hear a click, or the hammer completely falls onto the firing pin, you have a worn disconnector, hammer, or trigger and they need to be replaced.
Place the selector switch on safe and try to pull the trigger. The hammer should not fall. If it does there is a problem with your selector switch and/or trigger. >

The first time it made the disconnector noise then every other time no joy. So sounds like the disconnector is not releasing the hammer.

The disconnector isn't reliably capturing the hammer. This means its possible (though very remote) for the rifle to fire out of battery.
Here's some possible results: https://www.google.com/search?q=ar+o...battery+kaboom

On a milspec trigger group, this could be because the disconnector spring is installed upside down. I can't remember if this is possible on a Geiselle trigger...

Since the receiver is an 80% its also possible you have a trigger or hammer pin hole that is very slightly in the wrong location.

You will likely need to switch to a single piece drop in trigger. Something like a Timney. https://www.google.com/search?q=one+...+control+group

[Rocketrob]

Ok think we have it worked out.
Disassembled the lower. Noticed the installed trigger group was not the Geissele SSA I had purchased. Found the Gisele trigger and replaced the other one and now it will function check.
Upon examination of the budget trigger I could find nothing wrong.

Thanks for the help guys and will get her out to the range asap to confirm all go!

[damon1272]

The nose of the disconnector is a tad long. File a few thousandths off and it will work like a champ.