AR15 - Failure to extract / Light strike

Rivalen

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Hey all,

I recently bought my first AR from EE (I had shot AR15s before but this is the first time I own one). When I got it, I just did a quick field strip and lubbed the bolt carrier with breakfree clp, I did not go any further (like removing the bolt, firing pin, etc..). Yesterday I hit the range with a ####load of ammunition to try it out. Well... I managed to shoot like 15 rounds total and left the range kinda PO'ed...

Here is my issue:
1- Insert mag with bolt open.
2- Drop the bolt with the button on the receiver.
3- Shoot first round and second round, no problem.
4- 3rd round chambers, click. Nothing happens.
5- Pull the charging handle to clear it but it doesn't extract and crush the next round (Bump on it's side, on another round the bullet was pushed into the case a little bit, double feed caused by stuck round).
6- Removed magazine, the bumped round drops.
7- I tried running the charging handle a few times but it would not come out. Pulling the trigger would not shoot it either.

8- Sometime it would come out after pulling the charging handle a few times, sometime never and I had to remove it trough the ejection port with a screwdriver (I didn't have to use any force, just push it down and it would come out very easily).
9- At all time the stuck round were always light striked and alive. Spent rounds always extracted properly.

What I tried:
9- I tried changing to a diffrent mag, same issue.
10- I tried loading just 1 round or 2 round. I would have the same issue even on the first round.
11- I sprayed some CLP in the ejection port on the bolt carrier and ran the action a lot to make it "very wet" (It was already well lubbed imo). Same issue.

Notes:
1- On spent case the primer was clearly hit with a deep hole in it.
2- On stuck case the primer was just lightly hit with just a tiny bump in it.

Details:
- AR: Stag arms 2T with 1500 rounds
- Mags: Grey metal GI style 5/30 (rivet block)
- Trigger: Aftermarket Geissle SSA
- Ammunition: PMC Bronze 55gr FMJ brass cased (Recently bought from canadaammo).

All in all, I spent my range time unjamming the thing and trying to figure out what was going on... Thus making me an unhappy AR user...

As an AR noob I have searched the internet but haven't really found anything really similar to my issue, or maybe I just dont word my search properly... To me it seems to be extractor related. Did I just buy somebody else problems?

Thanks for the tips, any help would be appreciated... I could take pictures of specific parts or ammunition primers if you'd like to see it.
 
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First things first;

Try different ammo. I doubt the PMC is the problem, though.

The extraction issue does seem extractor related (call me Captain Obvious). Does the extractor seem 'loose' when you pull it away from the bolt? Is the 'claw' of the extractor chipped?

Examine the firing pin tip to make sure it's not broken or chipped.

As far as the light strikes......I'm hesitant to say it because I doubt it's the problem, but it could be too loose of headspace (round is entering the chamber too far)....but I doubt it.


Post pictures of the gun (chamber, bolt, extractor, firing pin).
 
I'm no expert. Hope these vids help.
I find PMC is loaded really light. Can cause issues if your gas rings are not 100%.

Check you gas rings.
Shows how to test gas rings at beginning of video.

[youtube]BpkzWhoaK04[/youtube]


Get Extractor upgrade kit

[youtube]XGx-6OXcu0Q[/youtube]
 
When you ran the charging handle on the stuck live round, did you guide the charging handle all the way forward of did you let it go and allow it to snap forward under spring tension? If you did the first, did you at least tap the forward assist? If not, you are probably lowering the bolt and not allowing it to close fully even though it may look closed from the ejection port.

If it's the second part, light strikes and failed extraction could be from:

a) worn or broken extractor (as pointed out by Malice) or weak spring tension on the extractor. Check the extractor hook to see if it is worn (not sharp) or damaged. If it looks fine, pick up the spring/o-ring upgrade kit.
b) gummed up firing pin. Disassemble the BCG and check for excess lube on the firing pin and firing pin channel in the bolt. Give it a good cleaning in some alcohol, naptha or whatever you use for degreasing. You don't want a bunch of lube on your firing pin etc.
c) Check the trigger. If your rifle came with a stock mil-spec trigger, check the pull weight. If it is lighter than 7lbs, chances are the previous owner swapped for a lighter hammer spring or modified it. Check and see if there are two hammer spring legs sitting on the trigger retaining pin. If there is only 1, the previous owner probably cut a leg off to reduce trigger pull and could result in light strikes. If there are two, and pull weight is under 7lbs, chances are it's a light hammer spring. Replace with a standard spring.
d) Gas leak. Check your bolt's gas rings for wear. Stand the full BCG on the bolt. If it slips in easily under its own weight, the rings are worn. Mind you, a rifle can cycle under worn rings still. Check the gas block to see if is loose. Next range session, load one round in a mag and shoot it. See if the bolt locks back on an empty mag.

What rifle is it? Home built or factory assembled?
 
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Also take a look at the chamber see if there is heavy fouling or is there is a defect. This rings of chamber issue easier dirt. Damage or spec.
the reason i say this as it seams as soon as the gun warms up it happens.
Also is it a match clambering?
This can be an issue at times; try a standard quality 223 ammo and see how it works.
bbb
 
The whole 'rings supporting the carriers weight' is wrong. Rather, you are supposed to remove the firing pin and cam pin and hold the carrier with the bolt facing down. If the bolt falls out under its own weight then the rings should be replaced.

https://www.google.ca/url?sa=t&sour...HXpasLjh1xWFT4y4w&sig2=9nAp5Y8RxOJk57_XuSxPDg

Page 0011-6

Having said that, that manual also mentions staggering the gaps in gas rings which has long ago been proven to be a myth so take it for what it's worth.
 
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When you ran the charging handle on the stuck live round, did you guide the charging handle all the way forward of did you let it go and allow it to snap forward under spring tension? If you did the first, did you at least tap the forward assist? If not, you are probably lowering the bolt and not allowing it to close fully even though it may look closed from the ejection port.

Option 1, and I did try the foward assist.

If it's the second part, light strikes and failed extraction could be from:

a) worn or broken extractor (as pointed out by Malice) or weak spring tension on the extractor. Check the extractor hook to see if it is worn (not sharp) or damaged. If it looks fine, pick up the spring/o-ring upgrade kit.
b) gummed up firing pin. Disassemble the BCG and check for excess lube on the firing pin and firing pin channel in the bolt. Give it a good cleaning in some alcohol, naptha or whatever you use for degreasing. You don't want a bunch of lube on your firing pin etc.
c) Check the trigger. If your rifle came with a stock mil-spec trigger, check the pull weight. If it is lighter than 7lbs, chances are the previous owner swapped for a lighter hammer spring or modified it. Check and see if there are two hammer spring legs sitting on the trigger retaining pin. If there is only 1, the previous owner probably cut a leg off to reduce trigger pull and could result in light strikes. If there are two, and pull weight is under 7lbs, chances are it's a light hammer spring. Replace with a standard spring.
d) Gas leak. Check your bolt's gas rings for wear. Stand the full BCG on the bolt. If it slips in easily under its own weight, the rings are worn. Mind you, a rifle can cycle under worn rings still. Check the gas block to see if is loose. Next range session, load one round in a mag and shoot it. See if the bolt locks back on an empty mag.

Will check a) b)
c) The trigger is an aftermarket Geissle SSA.
d) I tried shooting just 1 round from the mag. When I managed to shoot without malfunction I did have a locked bolt on last round.

What rifle is it? Home built or factory assembled?

It's a Stag arms 2T with a few upgrades like Geissle SSA trigger, CTR stock and raptor charging handle.

I'll get back with some more pictures..
 
According to the test I did (from the video), the gas ring are fine, although I've just watched the video, I think they're pretty much lined up so I'll have to fix this (Probably not an issue).

I have no reference but the extractor looks sharp and fine and the spring has some good tention (to my noob ar knowledge). I noted there was some brass particles at the chamber from the brass beeing eat by the extractor?

The firing pin was dirty and I cleaned up some crud at the end that had to be scraped off.

I did not check if the trigger spring have been cut...

Here are some images:

Extractor
IMG_1390.jpg


Bolt and firing pin
IMG_1391.jpg


Bolt face
IMG_1393.jpg


Bolt other end (There seems to be very hard crud there..)
IMG_1394.jpg


Ammo (1 spent case between 2 "light striked and failed to extract" live round). See how the case are eaten.
IMG_1395.jpg
 
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Not sure if it's the pic size but your firing pin tip looks a bit blunt. Maybe you can try a new firing pin?
The hard crud looks like carbon fouling. Use a bronze brush, some Nitro solvent and elbow grease on it.
I don't think the fouling is the problem, I've ARs with way worse than that!
 
The light primer strike on the outside cartridges in the PIC is totally normal. It happens when the round is chambered because the firing pin is free floating in the BCG and when the bolt closes the pin flies forward under its own momentum. Ok I'm totally rambling..... If you don't believe me just chamber a round, don't fire it and extract it for inspection (once you fix your extraction problem)
 
The light primer strike on the outside cartridges in the PIC is totally normal. It happens when the round is chambered because the firing pin is free floating in the BCG and when the bolt closes the pin flies forward under its own momentum. Ok I'm totally rambling..... If you don't believe me just chamber a round, don't fire it and extract it for inspection (once you fix your extraction problem)
All of my AR's have the slight primer strikes as you have described. It's normal.
 
According to the test I did (from the video), the gas ring are fine, although I've just watched the video, I think they're pretty much lined up so I'll have to fix this (Probably not an issue).

I have no reference but the extractor looks sharp and fine and the spring has some good tention (to my noob ar knowledge). I noted there was some brass particles at the chamber from the brass beeing eat by the extractor?

The firing pin was dirty and I cleaned up some crud at the end that had to be scraped off.

I did not check if the trigger spring have been cut...

Here are some images:

Extractor
IMG_1390.jpg


Bolt and firing pin
IMG_1391.jpg


Bolt face
IMG_1393.jpg


Bolt other end (There seems to be very hard crud there..)
IMG_1394.jpg


Ammo (1 spent case between 2 "light striked and failed to extract" live round). See how the case are eaten.
IMG_1395.jpg
Dont get so hung up on the ring alignment as they constantly rotate and never remain when the bolt is initially inserted. Hell an AR will cycle with only one gas ring.
 
Strip the entire rifle and thoroughly clean each piece along with the chamber. FYI A number of AR's require breaking in.
 
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Rounds that are chambered but not fired may have a small mark. But unless im reading it wrong, the OP is pulling the trigger,*click no bang*, and the primer has a light strike.

Try another brand of ammo. I know I have had issues with .50BMG PMC ammo that needed to be hit twice or that were 'duds'.

May not be the problem but try something like AE223 ammo and see if it does the same thing

I normally wouldn't question a Giesele trigger but maybe the light strike is a spring issue?
 
Rounds that are chambered but not fired may have a small mark. But unless im reading it wrong, the OP is pulling the trigger,*click no bang*, and the primer has a light strike.

Try another brand of ammo. I know I have had issues with .50BMG PMC ammo that needed to be hit twice or that were 'duds'.

May not be the problem but try something like AE223 ammo and see if it does the same thing

I normally wouldn't question a Giesele trigger but maybe the light strike is a spring issue?
Incorrect head spacing can prevent the extractor claw from fully engaging the rim after the BCG had chambered a round. The gap is great enough so the FP will not detonate the primer.
 
The whole 'rings supporting the carriers weight' is wrong. Rather, you are supposed to remove the firing pin and cam pin and hold the carrier with the bolt facing down. If the bolt falls out under its own weight then the rings should be replaced.

https://www.google.ca/url?sa=t&sour...HXpasLjh1xWFT4y4w&sig2=9nAp5Y8RxOJk57_XuSxPDg

Page 0011-6

Having said that, that manual also mentions staggering the gaps in gas rings which has long ago been proven to be a myth so take it for what it's worth.

Yep. First time see the correct way of testing gas rings on this forum actually...
 
Rounds that are chambered but not fired may have a small mark. But unless im reading it wrong, the OP is pulling the trigger,*click no bang*, and the primer has a light strike.

Try another brand of ammo. I know I have had issues with .50BMG PMC ammo that needed to be hit twice or that were 'duds'.

May not be the problem but try something like AE223 ammo and see if it does the same thing

I normally wouldn't question a Giesele trigger but maybe the light strike is a spring issue?

Exactly this; Insert mag, drop the BCG, click, no bang, pull the charging handle, no extraction.

Is it possible that the bolt pushes the round in without properly gripping the round with the extractor thus pushing the round in the chamber but the bolt face would be way to far from the ammunition's butt for the firing pin to actually hit the primer?!
 
Incorrect head spacing can prevent the extractor claw from fully engaging the rim after the BCG had chambered a round. The gap is great enough so the FP will not detonate the primer.

I've checked videos on headspace... This is a Stag arm rifle with it's stock BCG, "it should work" as is IMO. Unless my issues are ammo related (Which I highly doubt), I'm starting to think I bought a used rifle from someone who might have known those issues existed...
 
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