Problem with my AR10

[MuddvilleHustler]

I have a Dpms type.

I have had my Ar finished for about 6 months and finally went out today to get a shoot it and it would fire the first shot eject and would not fire the second round, I could pull the charging handle and put another round in and it would fire. The process would repeat.

A guy at the range said my trigger spring was to light and that my firing pin should be free floating and not but under tension from a spring.

[Hoop]

So you fire, round ejects, bolt is forward but it doesn't have another round in the chamber? Could be short stroking (not enough pressure to push the bolt all the way back) or an issue with your magazines.

[Don the savage]

Did you use a .308 buffer/spring? What type of stock? What type of mags?

[FMJBT]

Need more details. Parts configuration, more specific decription of the malfunction, ammunition type, moon phase, etc.

[shadowofnight]

I have a Dpms type.

I have had my Ar finished for about 6 months and finally went out today to get a shoot it and it would fire the first shot eject and would not fire the second round, I could pull the charging handle and put another round in and it would fire. The process would repeat.

A guy at the range said my trigger spring was to light and that my firing pin should be free floating and not but under tension from a spring.

Was the range guy 6'7" tall, around 400 lbs ?

Just a little while ago, my buddy told me a guy at the range he was at ( Probably San Joaquin Rifle Pistol range in Linden ) was having your exact same issues with an AR10.

As the others said, need more details as to what exactly the firearm is/isn't doing.

[MuddvilleHustler]

Wow that's him... I told him I was thinking that my buddy who helped me build it might have put in an Armalite bolt. I spoke to him and he said dpms but at this point I ma not sure if he is sure or not. like I said it was some time ago

I will put the mag in pull charging handle to chamber a round. It will fire, eject and chamber another round...pull the trigger and no fire. pull charging handle and eject the round, the new round will fire. I though the bolt may not be closing all the way so pushed the forward assist a few good times to make sure the bolt was all the way closed.

[MuddvilleHustler]

I found this when I searched 'how to tel the difference between a dpms bolt and an armalite'
Armalite and DPMS bolts are identical. One uses a silver chrome ejector, the other is black; but No Difference between the bolts.

Where there is a difference is the rear relief on the bolt carrier. The DPMS firing pin does not use a rebound spring, Armalite does. The DPMS carrier is about .15" longer. If using an Armalite firing pin w/DPMS carrier, remove the rebound spring. If using DPMS

FP in Armalite carrier must add the spring.

I have used complete DPMS coated bolt carrier group in Armalite rifle. No problem. Only dimensional difference is internal as mentioned above.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2857133

[FMJBT]

This doesn't sound like an issue with the firing pin or bolt. The rifle is ejecting the spent casing and feeding a new round into the chamber, so the gas system is likely not the culprit either. The thing I noticed is that when you cycle a round by hand, it fires. When it feeds after firing one round, the following round will not fire. I would take a look at the disconnector, it sounds like it is not catching the hammer after firing while there is still a finger pulling the trigger back. The trigger is probably riding forward with the bolt, without enough force to lite off the primer. Once the trigger is released and the weapon is cycled manually, the trigger resets to the firing position, ready to fire. Do the primers on the rounds that don't fire have indents on them from the firing pin lightly striking?

I had the same problem on my first AR-10, actually numerous problems but this was one of them. I was running a Jard single stage adjustable trigger, and it was failing to reset properly between shots. My rifle was essentially a bolt action gun that would shoot one out of every 2 rounds. I tried adjusting that Jard trigger for a long time before I gave up on it and just went with a standard DPMS trigger assembly. That fixed the reset issue, took me about another year of taking it to the range and troubleshooting to diagnose and fix all the other stuff that was wrong with it

[duc748bip]

I had the same thing happen to me but on a 9mm AR. I had to file the disconnect hook so it will catch the hammer. Looks like your bolt is not pushing the hammer low enough to be caught by the disconnect.

[MuddvilleHustler]

This doesn't sound like an issue with the firing pin or bolt. The rifle is ejecting the spent casing and feeding a new round into the chamber, so the gas system is likely not the culprit either. The thing I noticed is that when you cycle a round by hand, it fires. When it feeds after firing one round, the following round will not fire. I would take a look at the disconnector, it sounds like it is not catching the hammer after firing while there is still a finger pulling the trigger back. The trigger is probably riding forward with the bolt, without enough force to lite off the primer. Once the trigger is released and the weapon is cycled manually, the trigger resets to the firing position, ready to fire. Do the primers on the rounds that don't fire have indents on them from the firing pin lightly striking?

I had the same problem on my first AR-10, actually numerous problems but this was one of them. I was running a Jard single stage adjustable trigger, and it was failing to reset properly between shots. My rifle was essentially a bolt action gun that would shoot one out of every 2 rounds. I tried adjusting that Jard trigger for a long time before I gave up on it and just went with a standard DPMS trigger assembly. That fixed the reset issue, took me about another year of taking it to the range and troubleshooting to diagnose and fix all the other stuff that was wrong with it

Yes the second round has a dent in it but not enough to ignight the primer. Secondly the ones that do go off seem to have a light strike as well

[duc748bip]

Was it a light hammer strike on the second round or the hammer follow the bolt to rest and made a dent?

Yes the second round has a dent in it but not enough to ignight the primer. Secondly the ones that do go off seem to have a light strike as well

[Hoop]

Maybe check to make sure that the trigger is installed correctly? Doesn't sound like anything I've seen before.

[Dieseldog]

What type/make of trigger are you using?

[MuddvilleHustler]

The stock one that came in the lpk...

The all seemed to be light strkes

[vern748]

Did you use a .308 buffer/spring?

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