AR15 not firing second round

[mhayes]

One of my AR's has started giving me issues. This is a built gun, not a budget gun but not top shelf either. It's a 300 blackout with out suppressor. This gun has been running fine for years. But recently started giving me issues. I will try to explain it the best I can. Your first round is loaded manually by closing the bolt. It fires and ejects just fine. The new round gets loaded and everything appears to be fine. But it wont fire. You pull the charging handle back and it ejects the second, unfired bullet. You drop the bolt and it manually loads the third round and she fires just fine. The trigger wont pull on some of the auto loaded rounds, sometimes it will but there will be a slight mark on primer. Gun fires just fine when manually loaded by you. But the auto loads will not.

I have swapped mags, that didn't help. Changed bullets, nope. I do not run handloads, this is all factory rounds. Bumping the rear of charging handle and pushing the forward assist does nothing either.
Can this be a firing pin problem?
A gas block problem?
Or maybe a bolt carrier problem?

Any ideas?

Thanks,
Matt

 

[Torn]

cmshoot

 

[hunterofopportunity]

Take the bolt apart and clean inside firing pin area, also I would remove the buffer spring and inspect and clean the tube. Also being it fires when manually loaded could the bolt not be traveling far enough back to reset the trigger each time(maybe gas port clogged). Just where I would look first.

 

[cmshoot]

Could be an issue with the firing pin, or another part of the BCG.

Could be an issue with any one of several parts of your FCG.

Could be an issue where your barrel extension and/or chamber need cleaned. If there is something stuck in there, or it's excessively foul, and this condition prevents the bolt from fully going into battery, it would not fire.

Could be an ammo issue.

If you can bring it by TruPrep in Marietta, I can properly diagnose it.

 

[user 71]

May want to check that your hammer spring is installed in the correct orientation. If you didn’t have to fight the tension a bit while putting the hammer pin through, it may be installed backwards.

Also 300 blackout is notoriously finicky due to the wide variety of loads, bullet weights, velocities, gas system lengths, barrel lengths, etc. You mentioned shooting unsuppressed. Some combinations I have seen wouldn’t cycle unsuppressed due to lower dwell time and lower pressure of some 300 BO loads.

What barrel length, gas system, and ammo are using?

 

[Control for Smilers]

One of my AR's has started giving me issues. This is a built gun, not a budget gun but not top shelf either. It's a 300 blackout with out suppressor. This gun has been running fine for years. But recently started giving me issues. I will try to explain it the best I can. Your first round is loaded manually by closing the bolt. It fires and ejects just fine. The new round gets loaded and everything appears to be fine. But it wont fire. You pull the charging handle back and it ejects the second, unfired bullet. You drop the bolt and it manually loads the third round and she fires just fine. The trigger wont pull on some of the auto loaded rounds, sometimes it will but there will be a slight mark on primer. Gun fires just fine when manually loaded by you. But the auto loads will not.

I have swapped mags, that didn't help. Changed bullets, nope. I do not run handloads, this is all factory rounds. Bumping the rear of charging handle and pushing the forward assist does nothing either.
Can this be a firing pin problem?
A gas block problem?
Or maybe a bolt carrier problem?

Any ideas?

Thanks,
Matt

IF you load 1 round...does it lock back with an empty mag?

 

[mhayes]

IF you load 1 round...does it lock back with an empty mag?

I didn't go through the entire mag. Once I realized I had an issue, I played with it for awhile trying to find the issue. I can try that tonight. Thanks,

 

[mhayes]

Could be an issue with the firing pin, or another part of the BCG.

Could be an issue with any one of several parts of your FCG.

Could be an issue where your barrel extension and/or chamber need cleaned. If there is something stuck in there, or it's excessively foul, and this condition prevents the bolt from fully going into battery, it would not fire.

Could be an ammo issue.

If you can bring it by TruPrep in Marietta, I can properly diagnose it.

I have had the rifle for a few years and maybe put 200-250 rounds through it. Gun is clean, no fouling and or trash that I can see even after disassembling. I am leaning towards the BCG or Gas block. Another memeber mentioned that it may not go back farenough to reset the trigger. There was a time or two that even after it reloaded, the trigger would not pull. So I will take a look at the BCG and Buffer spring tonight.

I appreciate the offer to look it over. If I ever get down that way I will have to stop in and meet you. You have been kind and offered advise to me numerous times. Thanks for the info.

 

[David's Gun Room]

Yeah I agree with Shep, could be a variety of things. If truprep is too far we can always take a look at it too if that's closer and easier for you.

 

[popic]

did you ever find what the problem was?