I am having problem with the trigger on a 80% lower I am building. When I depress the trigger the hammer won't fall, but after depressing the trigger few times the hammer is released from sear upper hook to the next step and then with next trigger pull will release the hammer?hat

Help is greatly appreciated!!

ANYBODY PLEASE?

Come on 23 views and no a single response?

Can you post pics?  What lower parts kit did you use?

It sounds like the trigger is functioning as though the hammer was cocked with the trigger held...

Take it all aprt and do it again,following the instructions VERY closely. I put the trigger spring on backwards on my first build. Check out the tacked forum at the top of the page and review what you may have done wrong.
Good luck!

EAT: Check this out if you haven't already. I used this thread to build mine. Very Helpful!

http://www.ar15.com/forums/topic.html?b=3&f=4&t=226782

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Quoted: Can you post pics?  What lower parts kit did you use? It sounds like the trigger is functioning as though the hammer was cocked with the trigger held...

DPMS rings a bell?

Quoted: Pull the selector and see if the trigger will now work with out it. If yes, then you drilled something wrong on the reciever and will have to work a FCG to work with the missed drill lower receiver.

Whoah! Sorry,I missed the part about it being an 80% lower! I hope you get her running.

First, as Dano523 suggested, make sure its not the selector/safety holding up the trigger, as thats an easy and quick test.


If I had to make a guess though, it would be that the seer is too close to the hammer.  The seer should only be catching on the hammer while the trigger is held down directly after the hammer is pulled back.  Otherwise, there should be a gap.  

Think about the process the bolt and trigger assembly goes through when you fire the rifle.

1.  hammer is cocked and resting on the trigger, round in the chamber, seer is free.
2.  pull trigger, hammer is released, hitting the firing pin and ammo goes bang.
3.  BCG goes back, re-cocking the hammer,  Hammer is held in place by the seer.  BCG chambers next round on the way forward.
4.  You release the trigger.  Seer gets released and hammer rests on the trigger.  

So, the only time the seer should actually be on the hammer is when the trigger is being held back while the hammer is in the cocked position after a round has gone off and before you release the trigger after the shot.  The seer is there to make it impossible for the hammer to drop on the new round with out first releasing the trigger.

Now, if, and only if, the problem is the seer is staying engaged all the time, unless you work the trigger several times, you can adjust it some with a grinder.  This is very important that you do not take off too much metal, as well as you keep the angle the same.  If you do modify it too much, you'll have to get a new seer.  If you grind your seer down too much, it is likely that you'll fire more than one round per trigger pull.  Some people think that may be the thing to do, but 1. your rifle and BCG isn't made to withstand full auto and you'll likely hurt yourself or someone around you.  2. the ATF will mess you up bad and not only will you never be able to own another firearm, but it is likely you also wont see the light of day for a very long time/be in debt the rest of your life.  3. the rifle is missing the other necessary items to make full auto safe.

Since the hammer does actually release, I dont think it is too much out of spec, but could be just enough to keep the seer locking the hammer all the time, unless its worked out.  I have about 1mm space between my seer and hammer when its not engaged. No clue what the stock triggers in kits have though.  I know that with my JP trigger, they specifically make you adjust the seer.  

To really get a better idea, I think we're going to need some pics though.  It also might be nice to know what type of trigger you have installed.  

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Quoted: First, as Dano523 suggested, make sure its not the selector/safety holding up the trigger, as thats an easy and quick test. If I had to make a guess though, it would be that the seer is too close to the hammer.  The seer should only be catching on the hammer while the trigger is held down directly after the hammer is pulled back.  Otherwise, there should be a gap.   Think about the process the bolt and trigger assembly goes through when you fire the rifle. 1.  hammer is cocked and resting on the trigger, round in the chamber, seer is free. 2.  pull trigger, hammer is released, hitting the firing pin and ammo goes bang. 3.  BCG goes back, re-cocking the hammer,  Hammer is held in place by the seer.  BCG chambers next round on the way forward. 4.  You release the trigger.  Seer gets released and hammer rests on the trigger.   So, the only time the seer should actually be on the hammer is when the trigger is being held back while the hammer is in the cocked position after a round has gone off and before you release the trigger after the shot.  The seer is there to make it impossible for the hammer to drop on the new round with out first releasing the trigger. Now, if, and only if, the problem is the seer is staying engaged all the time, unless you work the trigger several times, you can adjust it some with a grinder.  This is very important that you do not take off too much metal, as well as you keep the angle the same.  If you do modify it too much, you'll have to get a new seer.  If you grind your seer down too much, it is likely that you'll fire more than one round per trigger pull.  Some people think that may be the thing to do, but 1. your rifle and BCG isn't made to withstand full auto and you'll likely hurt yourself or someone around you.  2. the ATF will mess you up bad and not only will you never be able to own another firearm, but it is likely you also wont see the light of day for a very long time/be in debt the rest of your life.  3. the rifle is missing the other necessary items to make full auto safe. Since the hammer does actually release, I dont think it is too much out of spec, but could be just enough to keep the seer locking the hammer all the time, unless its worked out.  I have about 1mm space between my seer and hammer when its not engaged. No clue what the stock triggers in kits have though.  I know that with my JP trigger, they specifically make you adjust the seer.   To really get a better idea, I think we're going to need some pics though.  It also might be nice to know what type of trigger you have installed.

Whoao Manlaan!! You went straight to the point I think, I'll try to fix the sear and will let you know, definetely like you say as the hammer is eventually falling is out of specs by few thous's of an ". The whole lower kit is a DPMS.

BTW: After pounding the situation a lot I came to the same conclusion, so let's see if we are right.

Thanks a lot for that indepth information!!

If you do need to adjust the seer, just make sure you do lots of function tests and only remove a very tiny bit at a time.  JP Trigger Instructions should give you a pretty good idea about how to do the function tests, as well as how to adjust the seer.  Just ignore the parts about adjusting the trigger because you cant, of course.  Testing the disconnecter and Timing the disconnecter are the sections most relevant I believe.