Ar-15 trigger problem

F

FALacy

Moderator
I'm having an issue with my DPMS lr-308. I bought some lightweight trigger springs and I put them in, and when I got done assembling the trigger, I pulled back on the hammer and the top of the sear didn't engage the hammer. The bottom part of the trigger that the hammer hooks onto hooks up, but the hook part of the sear won't reach the notch on the hammer.

When I pull the trigger all the way, and then pull back on the hammer it will hook onto the sear as long as I have the trigger pulled all the way, but as soon as I let go, it moves forward off the sear and hangs onto the bottom notch on the trigger, and then when I pull it again and let go it will release the hammer.

So basically the only way for the hammer to engage the sear is if I pull the trigger, don't let go, and push the hammer onto it.

I obviously cannot shoot the gun when it is in this condition. Any help would be greatly appreciated!

Also - it isn't the springs, I put the factory ones back in and it still does it. I just must not be assembling it right. And yes, the pin with the notches the notches are on the left of the reciever when looking down the gun.
 
springs

Are you sure the hammer and trigger springs are on the right way. It is possible to slip the trigger spring on wrong and over the top (loop in trigger spring on the top and not under the trigger) of the sear and trigger instead of underneath.
 
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First of all, DPMS LR308 sounds like an AR-10.

Secondly, it sounds like someone has tried to do a trigger job and the hammer follows the bolt down when you try to fire the rifle. You need to call DPMS and find a service center near you or get the rifle to a smith to replace either the hammer or the trigger.
 
Yes the disconnecter spring is in.

And Scorch, I never said anything about shooting the rifle, or it 'following the bolt'. Armalite makes AR10's this is a DPMS lr-308, and they have the same trigger group as an ar-15 so the point it moot. Thanks for the help anyways though.


Is there a wrong way to put in the disconnecter spring? I wouldn't think so, but I can take it out and try again. Maybe I should take a picture of the trigger group assembled and disassembled?
 
ar trigger problem

I have had a similar problem with some of my ars. Definitely dont shoot it like this, you will probably get a burst going. That can be big trouble. I would replace the entire fcg.If it still does it absolutely sned it back to the factory, your pin holes might be out of spec. Check the disconnector spring, they can actually be put in upside down. This happened to me with my first ar. three round burst later got it figured out. I would avoid the light weight springs altogether. Stick with a standard spring and just polish the parts, I use a felt wheel with jewelers rouge. Dont let any heat build up. I had a light spring just recently and it turned out to be crappy parts quality. It would actually cause a static position in the trigger/ hammer cycle. The hammer and trigger have to be driven fast enough by the springs to get to their lock positions and not miss each other. If the hammer moves faster than the trigger reset you will be rockin and rollin. dont be afraid to buy several sets of parts. You should replace the internals at certain intervals anyway. And parts definitely can break, chip or warp. Be careful and keep asking questions.
 
trigger.gif

Is the channel in the top of the trigger clear of debris? Debris in the forward end of the channel will prevent the disconnector from rotating forward and catching the hook on the back of the hammer.
 
If you read what he says I think he is a bit confused as how the FCG on an AR works. It is working properly if it is doing what he says it's doing. I think he is talking about the disconnector when he says sear. There is technically no sear at all in a semi-auto AR FCG. There is the hammer, trigger, and disconnector.

The hammer will only catch the disconnector when the trigger is held back as he states and if you don't touch the trigger and pull the hammer back it will catch the machined surface on the trigger and catch but not catch the disconnector just as he says.

The reason the disconnector catches when your holding the trigger back is so the hammer won't follow the bolt when your holding the trigger back when firing. Then when you let go of the trigger the hammer falls onto the trigger and catches then you pull the trigger and drop the hammer.

Your AR is working the way it is suppose to work.
 
I concur with impalacustom. When the trigger is held down while the hammer is re-cocked, it is supposed to be caught by the disconnector. Then when you let up on the trigger, you should hear a click as the hammer is caught by the trigger sear. After that you should be able to depress the trigger and cause the hammer to fall.
 
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