Perfectly consistent malfunctions & extractor spring question

[Benito]

Hey Guys (and gals?),

I'm having some problems that I was hoping your collective experience and knowledge would be able to shed some light on.

I just got back from the range after trying out my 11.5" AR build (entirely consisting of quality known parts) for the first time.

Major parts:
Aero Precision Lower
Noveske Upper
DD 11.5" barrel
BCM Pow Profile Gas Block
Fail Zero BCG
Quality Mags (PMags and D&H, same problem happens regardless of mag type)

After each and every round fired, I am seeing what looks like a double feed, but isn't - rather it is a new round fighting for the chamber space with a spent round).

Now, I wasn't able to take pics or video of this, unfortunately, but in my amateur analysis, what is happening is either the extractor jumping over the rim as the bolt goes back, or the ejector not doing its job.

As for fixing this:
- I've ruled out a heavier buffer weight, because I am already running the heaviest buffer I can find, Slash's XH buffer. It's even heavier than the H3.
- The bolt locks back on an empty mag, so short-stroking is not the issue.
- While the ejector spring may be the culprit, I have a feeling that it could be the extractor spring, as that seems to be a more common occurrence from what I have read.

Now I have 2 questions:

1) Since the spent case is being successfully extracted from the chamber, is it possible for the extractor to jump over the rim AFTER the case is out of the chamber?

2) I have the BCM Extractor Spring Upgrade Kit. Embarrassingly, I must ask, is there such a thing as installing the extractor spring upside-down or right-side-up? Does it even matter? The reason I ask is that when I try to put in the BCM spring one way, it won't fit into the extractor hole (I've pressed into it like a mother****er, with no success), and the other way it fits easily, but fits loose and does not stay put.

[uncle money bags]

Are you using an o-ring with the extractor spring? If not, add it on and try again. Had the same problem with my mk18, the extractor was slipping by the case rim leaving the spent case in the chamber.

[Benito]

Are you using an o-ring with the extractor spring? If not, add it on and try again. Had the same problem with my mk18, the extractor was slipping by the case rim leaving the spent case in the chamber.

I was not using an O-ring, but before I use that, I would like to know whether I can install the spring "upside-down" or if it even matters.
Also, as I stated in the post, the spent case was not stuck in the chamber. One of my questions was if it is possible for the extractor to be the problem despite being able to pull the case out of the chamber (possibly jumping the case after).

[Clint]

I was not using an O-ring, but before I use that, I would like to know whether I can install the spring "upside-down" or if it even matters.
Also, as I stated in the post, the spent case was not stuck in the chamber. One of my questions was if it is possible for the extractor to be the problem despite being able to pull the case out of the chamber (possibly jumping the case after).

Yes, spring orientation matters.

The fatter end goes into the extractor pocket.

It may take a little force.

To clarify the original problem.

You are seeing two loose cases trying to chamber, one spent and one live?

Sounds like the ejector pin sticking.

Verify it moves freely.

The other possibility is a bad lip on the extractor that lets go as soon as the case clears the chamber but not the extension.

[Iraqgunz]

You are experiencing a failure to extract which then leads to a failure to feed. That is why the spent round is still in the chamber.

Your weapon then continues with the rest of the cycle of operation and feeds the next round into the casing.

More than likely it is something simple such as an extractor spring that is improperly installed, worn or weak. I would replace the extractor spring assembly first, before adding an O-ring.

Make sure to check the extractor itself that it is sharp and there are no chips, burrs, etc...

If none of the works then you may need to look at the chamber.

I noticed you didn't mention the buffer and spring. I would go ahead and get at least an H2 if not H3 buffer now as you will more than likely need one. I also recommend a blue Springco spring as well.

[Joe Mamma]

Yes, spring orientation matters.

The fatter end goes into the extractor pocket.

It may take a little force.



I'll just add that in my experience, you always hear a snap or click when the spring is fully (properly) seated.

Some people use pliers and squeeze the spring into the pocket. I've never had to do this. But if you use do, be gentle so you don't mess up the spring.

The spring insert goes in with the fat side against the extractor too.

I also agree that it *might* be a defective or worn extractor. But I doubt it because you don't mention any problem before the extractor spring change.

Looking on the bright side, this problem should be relatively easy to fix.

Joe Mamma

[Benito]

Hey fellas,

Thanks for the input.

Couple of points:
- The entire BCG is brand new, so wear shouldn't be an issue.
- The exact same problem persists with the BCG extractor and my spare extractor (both are brand spanking new). This leads me to think that it must be the spring, rather than the extractor claw.
- Like I said before, the buffer I'm using is heavier than an H3 (it's one of Slash's/HeavyBuffers.com XH buffers)

I will try it out again in a few days with the BCM extractor springs, and let you guys know how it goes.

Thanks again.

[AKDoug]

Do you have another bolt carrier group you can try? That might tell you what's going on.

[Failure2Stop]

If you have a side by side "double feed", one live and one fired, you have ejector issues.
This can be due to weak ejector spring pressure, excessive extractor spring tension, excessive BCG velocity, or an incorrectly assembled bolt/BCG.

I would lubricate and clean the ejector.

Putting an o-ring extractor upgrade into a gun with this issue will make it worse. The time to "improve" extractor tension is if the extractor is failing to extract the fired case from the chamber.

If the ejection and bolt velocity are out of synch you can bounce fired cases back into the ejection port, but this is usually observed as a stove-pipe.

Rarely, the bolt can be installed "reversed", with the extractor facing into the receiver left side instead of toward the ejection port. Requires disassembly to correct.



Typos brought to you via Tapatalk and autocorrect.

[Benito]

Do you have another bolt carrier group you can try? That might tell you what's going on.

Actually, I tried my other BCG, but the exact same thing happened, as the the both BCG's are the exact same make, and presumably have the same spring, etc.


If you have a side by side "double feed", one live and one fired, you have ejector issues.
This can be due to weak ejector spring pressure, excessive extractor spring tension, excessive BCG velocity, or an incorrectly assembled bolt/BCG.

I would lubricate and clean the ejector.

Putting an o-ring extractor upgrade into a gun with this issue will make it worse. The time to "improve" extractor tension is if the extractor is failing to extract the fired case from the chamber.

If the ejection and bolt velocity are out of synch you can bounce fired cases back into the ejection port, but this is usually observed as a stove-pipe.

Rarely, the bolt can be installed "reversed", with the extractor facing into the receiver left side instead of toward the ejection port. Requires disassembly to correct.



Typos brought to you via Tapatalk and autocorrect.

Hmm, interesting. Come to think of it, all except one of the stoppages were one-on-top-of-the-other. I had one stovepipe.
I am very curious to find out what the problem is.
I will definitely clean and lube the hell out the ejector, just to make sure, and give it a run with the new springs installed.
By Wednesday evening, I'll get back to you guys with an update.

[sinlessorrow]

What does the gas port on that DD barrel look like?

[Benito]

What does the gas port on that DD barrel look like?

No idea.


ISSUE RESOLVED!!

Put in the BCM upgraded extractor spring (no O-rings required). Ran like clockwork. Zero failures of any kind. Perfect and consistent ejection.
Very relieved that the fix was so simple.
Will email FailZero to let them know that their BCG's would be even more excellent if they just put in one tiny, little, inexpensive but very important spring.
Otherwise, the BCG is pretty nice. I have no qualms about regular phosphate BCG's, but got this one at a reasonable price when the drought was in full swing. Cleaning is pretty quick, but no way would I run it dry. Lube is a must. Who knows, maybe if your upper was also the same finish, then maybe you could try going dry. But I'd err on the side of lube.

[Bluedreaux]

I didn't want to start another thread, when it sounds like I'm having the same issue as the OP.

PSA upper and BCG. 16" mid-length gas. A5 buffer and spring. Factory .223 ammo. The bolt locks back on an empty mag, I don't believe I'm short stroking. I've got about 900 rounds on the set up, started having the same consistent malfunction at around 700.

I've cleaned the bolt, removed the extractor and cleaned it. The ejector is moving freely. A friend, who's a fair bit more experienced than I, took a look and said the extractor felt "very weak". I've got a BCM bolt upgrade kit on the way from Grant that I'll try next week.

OP, is this what your malfunction looked like? Any other ideas on a solution from anyone? This is the only malfunction of any kind I've experienced with this AR and the malfunction has been the exact same every time.

The top round is fired, it extracted but didn't eject. The bottom round is stripped off the magazine.

http://i192.photobucket.com/albums/z118/Bluedreaux/0483986D-7B73-4636-8105-92E9ABE4B4F9-963-000001ACE81CDFA0_zpseb89af9d.jpg

These are the two rounds from the above pic. The fired round has marks on it's 12 o'clock, the fresh round has marks at it's 6 o'clock.

http://i192.photobucket.com/albums/z118/Bluedreaux/452095C4-F9E2-4489-BC7C-9E3D5C7A11FB-963-000001ACF7E10EA5_zpsf7b22ddb.jpg

[Failure2Stop]

Yup, you have classic mis-timing in ejection and bolt velocity, though I normally jump straight to weak ejection when I see that.
Extractor tension might be too high, ejector tension might be too low, or a combination of those two or other factors.

The dents on the rounds are from being jammed into the barrel extension lugs.

[Benito]

Hey Bluedreaux,

That is extremely close to what my issue looked like. Wish I took pics myself, but yours is almost identical to what I had going on except for one thing:
If I recall correctly, for me it was the fresh round getting stuck on top of the spent one rather than the other way around, like you describe.

Failure2Stop mentioned bolt velocity and mis-timing. My question is that if your gun is a mid-length, and using a decent weight buffer (and what I presume to be a FA BCG), your bolt velocity shouldn't be way out of whack, unless your gas port is way oversized.

For me, the fix was straightforward, as I hope yours is too.

Keep us posted.


I didn't want to start another thread, when it sounds like I'm having the same issue as the OP.

PSA upper and BCG. 16" mid-length gas. A5 buffer and spring. Factory .223 ammo. The bolt locks back on an empty mag, I don't believe I'm short stroking. I've got about 900 rounds on the set up, started having the same consistent malfunction at around 700.

I've cleaned the bolt, removed the extractor and cleaned it. The ejector is moving freely. A friend, who's a fair bit more experienced than I, took a look and said the extractor felt "very weak". I've got a BCM bolt upgrade kit on the way from Grant that I'll try next week.

OP, is this what your malfunction looked like? Any other ideas on a solution from anyone? This is the only malfunction of any kind I've experienced with this AR and the malfunction has been the exact same every time.

The top round is fired, it extracted but didn't eject. The bottom round is stripped off the magazine.

http://i192.photobucket.com/albums/z118/Bluedreaux/0483986D-7B73-4636-8105-92E9ABE4B4F9-963-000001ACE81CDFA0_zpseb89af9d.jpg

These are the two rounds from the above pic. The fired round has marks on it's 12 o'clock, the fresh round has marks at it's 6 o'clock.

http://i192.photobucket.com/albums/z118/Bluedreaux/452095C4-F9E2-4489-BC7C-9E3D5C7A11FB-963-000001ACF7E10EA5_zpsf7b22ddb.jpg

[Bluedreaux]

Yup, you have classic mis-timing in ejection and bolt velocity, though I normally jump straight to weak ejection when I see that.
Extractor tension might be too high, ejector tension might be too low, or a combination of those two or other factors.

So what's a recommended solution? A stronger extractor spring would only exacerbate the problem...(?). New ejector spring? I've got a bolt upgrade kit coming, but it doesn't come with an ejector spring.

I've got a BCM BCG on the way, when it arrives I'll try it to see if it's maybe a timing/buffer issue. I'll also compare the ejector strength. Anything else?

[Failure2Stop]

So what's a recommended solution? A stronger extractor spring would only exacerbate the problem...(?). New ejector spring? I've got a bolt upgrade kit coming, but it doesn't come with an ejector spring.

I've got a BCM BCG on the way, when it arrives I'll try it to see if it's maybe a timing/buffer issue. I'll also compare the ejector strength. Anything else?

Here is where I would start the diagnostic process:

If you have an o-ring around the extractor spring, remove it.
Put a drop of lube in the bolt face right beside/on the ejector and work it in and out for a while. Soft brass can get shaved off and clog up the ejector, look for flakes of brass working out. You can do it with a dummy round, spent case, or just a tool that fits that won't mar/scratch the parts. Note ejector tension, it should take positive effort to depress the ejector.

If you don't have prior experience with pulling the ejector I wouldn't recommend doing it until you have the right tools and knowledge.

It is definitely possible that there is another issue, this addresses the "easy fix". Very well may require further work.

ETA: have you checked your fired case case-head? Look for a semi-circular smear that corresponds with the ejector, might be indicating that your brass is soft, that you have a burr on the ejector, or that you are having excessive pressure issues.

[BufordTJustice]

Here is where I would start the diagnostic process:

If you have an o-ring around the extractor spring, remove it.
Put a drop of lube in the bolt face right beside/on the ejector and work it in and out for a while. Soft brass can get shaved off and clog up the ejector, look for flakes of brass working out. You can do it with a dummy round, spent case, or just a tool that fits that won't mar/scratch the parts. Note ejector tension, it should take positive effort to depress the ejector.

If you don't have prior experience with pulling the ejector I wouldn't recommend doing it until you have the right tools and knowledge.

It is definitely possible that there is another issue, this addresses the "easy fix". Very well may require further work.

ETA: have you checked your fired case case-head? Look for a semi-circular smear that corresponds with the ejector, might be indicating that your brass is soft, that you have a burr on the ejector, or that you are having excessive pressure issues.

All great advice. OP, also focus on the ejector smear and if there is an extreme flattening of the primer...or if the primer actually starts to flow into the firing pin hole (it will look and feel like a small ring/ridge around the firing pin indentation). Those are pressure issues and would help us steer your troubleshooting. Let me look for a picture....

[BufordTJustice]

http://www.ar15barrels.com/tech/overpressure.jpg

&
http://imageshack.us/photo/my-images/43/6mmnorma1.jpg/?sa=0 (http://imageshack.us/photo/my-images/43/6mmnorma1.jpg/?sa=0)

Photo credit for the first image goes to AR15barrels.com

And here is an image that shows primer material flowing into the firing pin opening:
http://i255.photobucket.com/albums/hh133/counterclockwisester/pressure_signs_for_sure.jpg

[Inix]

Hey Bluedreaux,

That is extremely close to what my issue looked like. Wish I took pics myself, but yours is almost identical to what I had going on except for one thing:
If I recall correctly, for me it was the fresh round getting stuck on top of the spent one rather than the other way around, like you describe.

Failure2Stop mentioned bolt velocity and mis-timing. My question is that if your gun is a mid-length, and using a decent weight buffer (and what I presume to be a FA BCG), your bolt velocity shouldn't be way out of whack, unless your gas port is way oversized.

For me, the fix was straightforward, as I hope yours is too.

Keep us posted.

Same thing happened to me today with a PSA 14.7 6.8 mid with S&B factory ammo. At first I was thinking it might be some sort of buffer/spring issue but I will try to address the ejector/extractor first and see how that goes. For me it was the spent on top of the fresh, the spent round would get jammed angling more nose up than what is in the pictures. Brass and rounds would get beat up bad. Hopefully one of these fixes will work.

[Iraqgunz]

Not sure of you noticed, but this thread is over 18 months old.


Same thing happened to me today with a PSA 14.7 6.8 mid with S&B factory ammo. At first I was thinking it might be some sort of buffer/spring issue but I will try to address the ejector/extractor first and see how that goes. For me it was the spent on top of the fresh, the spent round would get jammed angling more nose up than what is in the pictures. Brass and rounds would get beat up bad. Hopefully one of these fixes will work.