10.5" LMT + Norinco 5.56 = FTE?

Kieran

Kieran

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I recently got a case of that Noric ammo that is all the rage. I tried it with my 16" DD upper with good results. Maybe 75 rounds and no issues.
Today I took my 10.5" LMT out to try a new GA trigger I put in last night. In maybe 25 rounds I had 4 failures to eject. This is on a rifle that has had maybe 5000 federal rounds through it without any issues.
The failure to ejects were fairly mild. Meaning they cleared easily. The last one took everything I had left to clear. I tried wrenching on the charging handle, hooking the bolt with my MUT and mortaring it all to not avail. I managed to remove the upper and lower and using a screwdriver and some cardboard pry the bolt back mm by mm. The case looked fine, no damage by dim light. What I was encountering was a failure to eject and a double feed. The second round would get squashed and the bullet would get forced into the casing.
Any ideas oh great AR gurus of the CGN???
Thanks for the help.
Sorry for the bad spelling and sentence structure. I am on the iPhone and have far thumbs.
K
 
My wifes LMT def 2000 10.5" rock and rolled the norc 223. Chamber clean? no crude in there? how does you extractor look?

I got really rotten case of norc ammo (brass corroded) and last time out the DD and LMT didn't have an issue couple hundred rounds.
 
The chamber looked clean when I glanced down it. The extractor was intact and the spring still functioned. It was weird how stuck it got. I will do a detailed cleaning and inspection. I did a good cleaning maybe 100 rounds ago and i run them nice and wet. What would cause it to get so damn stuck?
 
I had an issue with my LMT BCG as well with the Norc ammo.

Take your bolt apart and pull out the little rubber washer around the extractor spring. It's what solved my failure to extracts on the Norc ammo.
 
I did a complete cleaning of the BCG and chamber. No damage to the locking lugs. The chamber had grime in it but nothing too bad. The locking lugs were clear when it got stuck so i am 90% sure it was the brass that had stuck in the chamber. Not sure why it was so stuck that it took the world to clear. It was last cleaned 100 rounds max ago. Cleaned the bolt and checked the extractor. Functions well, lots of spring tension. I am puzzled. Very puzzled. Now one thing I did do was install a Giesslie trigger in it. The touted faster lock time would have no effect on extraction as that would be in relation to the gas system, BCG and more so the extractor itself.

BCShooterGuy said:
Is your chamber 5.56 or .223?
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5.56. But by some accounts it's closer to min spec rather than max spec.

Farmboy said:
I had an issue with my LMT BCG as well with the Norc ammo.

Take your bolt apart and pull out the little rubber washer around the extractor spring. It's what solved my failure to extracts on the Norc ammo.
Click to expand...

I will try that. We're you getting then stuck in your chamber or was it just not grabbing them?
 
Similar issue. I've had stuck rounds with the Norinco 5.56 ammo also, but they were a failure to fully chamber a live round. The bolt got locked in place just slightly out of battery. I could not get the bolt to come back with the charging handle to cycle the round out. Although not the best solution, I was able to use the forward assist to force the bolt into battery and fire the round. I think this has happened at least twice with the Norinco ammo, and never with any other hundreds of rounds of .223 ammo I have put through it.

I still have a few hundred rounds of it left, and am debating if I am going to use it in my AR or not.
 
I will try that. We're you getting then stuck in your chamber or was it just not grabbing them?
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It wouldn't extract the empty brass from the chamber, and then strip off another round.

So, bolt to the rear, mag out, get the live crushed round to drop free, release the bolt and then #### it again. It would usually clear the empty brass by doing it manually.
 
Hard military primer on Norc ammo? Might explain the FTF.

Measure the base of the brass on that ammo. The jammed round sounds like the problem reloaders get when shooting resized brass that was previously shot in a sloppy semi auto chamber. The base becomes a bit wider and you get stuck rounds fail to eject etc when put in a semi such as an AR10 with a fairly tight chamber.

Sounds like Chinese barn spec might be at play with that ammo. I would run it through a Tavor or other semi auto that doesn't have as tight tolerences as a high grade AR.

Norc ammo in a LMT? Blasphemy!! I feel guilty feeding mine Dirty bird tactical.
 
Here's a theory and it's kind of out there. I too have an LMT 10.5". Haven't run any or my norc stuff through it yet, but I'll give it a shot next time I'm out at the range.

You said you had a failure to eject, but it sounds more like a failure to extract. Could it be that since the 10.5" guns are over-gassed and have a shorter dwell time and the norc ammo is hot that the gun is unlocking and trying to extract while the brass is still expanded in the chamber?

Like I said it's just a theory.
 
I had similar issues after going from a 16" to 10.5" barrel AR. I asked my trusted armourer and he was kind enough to swap the little blue extractor spring/bushing/washer whatever, to a more robust Black one. Any FTE, FTF problems disappeared. I'm not an expert by any means, I also read recently how a heavier buffer and buffer spring can help, by increasing dwell time enough for brass to rebound and to allow for easier extraction. YMMV.

I
 
I am going to try removing the donut like farmboy said worked for him. I will also order a new extractor and spring kit just in case. I am unsure how to address the rounds getting stuck. I cleaned the #### out of my chamber to the point where it was a mirror finish. Man does chrome lined really clean up well. I am unsure as how to proceed. I am not used to systemic failures such as this.
K
 
Throttle_monkey1 said:
Here's a theory and it's kind of out there. I too have an LMT 10.5". Haven't run any or my norc stuff through it yet, but I'll give it a shot next time I'm out at the range.

You said you had a failure to eject, but it sounds more like a failure to extract. Could it be that since the 10.5" guns are over-gassed and have a shorter dwell time and the norc ammo is hot that the gun is unlocking and trying to extract while the brass is still expanded in the chamber?

Like I said it's just a theory.
Click to expand...

Sounds like a decent theory to me. If the brass turns out to be in spec then this sounds possible.
 
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