Recognizing Extraction/Ejection Issues

[MistWolf]

Judging by the number of threads asking for help troubleshooting an empty case and live round stuck in an AR action (often mistakenly called a "double feed") it's safe to say it's a common malfunction. It is also one of the most misdiagnosed problems. As soon as someone posts to ask what cause this, folks start going on about what kind of ammo is being used or suggest heavier buffers & new action springs and trying a different magazine. Others will blame it on over-gassing or short stroking (I've been guilty of the latter a couple times myself). But none of these things will fix the real problem- weak extraction/ejection. Usually the problem is weak extraction.

First, let's talk about the most common misdiagnosis and get it out of the way- Over-gassing leading to the extractor jumping the case rim. If over-gassing is causing the extractor to jump the rim, the extractor and/or spring is failing. If the extractor & spring were both good, the extractor would tear the rim before jumping it. I've seen this first hand when pogo-ing the rifle to remove stuck cases from the chamber. If the case won't come out, the extractor will tear the rim off. While tuning an over-gassed AR will often eliminate the extractor jumping the rim, it's just a matter of time before extraction fails completely. The violence of an over-gassed action just reveals extraction problems sooner. So really, changing buffers, action springs or ammo won't fix the problem, they will only hide it.

Neither will short stroking cause this problem. I thought the empty/live round malfunction of a shortie I was trying to get dialed in was due to short stroking. This misdiagnosis was making me crazy, as I kept trying to tune the adjustable gas block for reliable ejection with softer recoil. Turned out the real problem was a flat extractor spring. The bolt was replaced and suddenly, tuning became a snap.

If the malfunction is due to short stroking and the extractor & ejector are in good shape, the case will eject long before the BCG travels rearward enough to push the next round out of the mag. The empty will eject when the BCG is about halfway to the rear. The bolt will have to travel almost all the way to the rim before it can enough grip to push the case. If the rifle suffers a failure to feed from short stroking, the empty will be ejected.

Next time someone asks about their AR jamming with an empty/live round caught in the action, remember, it's not from over-gassing, short stroking, ammo, action spring or buffer. It's either the extractor or the ejector. That doesn't mean the rifle doesn;t have other problems. But those won't be easy to find & fix until the extraction/ejection issues are solved.

One last thing- Nearly every rifle I've seen that suffered from this malfunction was due to weak extraction, so check that first

[Clint]

Youre right on with this one Mistwolf.

The difference between a good extractor spring setup and a bad one can be like night and day or very subtle.

The bad one can malf every round with certain ammo and seemingly run fine with different ammo.

The extractor should be firm, but not too firm.

A "rifle" type extractor spring is often/generally not strong enough without some help from an o-ring.

If the extractor takes shavings from every case rim, an extra heavy spring with an o-ring are the likely culprits.

A "5-coil", "gold", or "heavy duty" extractor spring without an o-ring is a great starting point.

[BufordTJustice]

Youre right on with this one Mistwolf.

The difference between a good extractor spring setup and a bad one can be like night and day or very subtle.

The bad one can malf every round with certain ammo and seemingly run fine with different ammo.

The extractor should be firm, but not too firm.

A "rifle" type extractor spring is often/generally not strong enough without some help from an o-ring.

If the extractor takes shavings from every case rim, an extra heavy spring with an o-ring are the likely culprits.

A "5-coil", "gold", or "heavy duty" extractor spring without an o-ring is a great starting point.
Agreed with you and Mist. I have had great experiences with SprinCo 5 coil, Colt copper washed, and Wolff XP extractor springs with black inserts and no o-rings.

[MistWolf]

Thanks for mentioning the extractor spring & insert, guys. I meant to bring up the Colt 5 coil copper colored spring in my first post, but somehow dropped the ball.

Let me add, that if the extractor spring needs an O ring, it's too weak and needs to be replaced. The best spring I can vouch for (I have no knowledge or experience with the others) is the above mentioned Colt spring. It comes with a black insert and is to be used without an O ring

[Iraqgunz]

I think you meant extractor.


Thanks for mentioning the ejector spring & insert, guys. I meant to bring up the Colt 5 coil copper colored spring in my first post, but somehow dropped the ball.

Let me add, that if the ejector spring needs an O ring, it's too weak and needs to be replaced. The best spring I can vouch for (I have no knowledge or experience with the others) is the above mentioned Colt spring. It comes with a black insert and is to be used without an O ring

[MistWolf]

HA! You're right. I'll go back & fix it.

Note to self: Proofread Twice; Post Once. I just got an infraction on another site for a typo. You'd think I'd learn

[tom12.7]

Extractor springs and o-rings can be an in depth subject onto themselves. I do not see the concept of o-rings as a total net negative. Many times it can be beneficial in operation of the platform, but that depends on some things. Material selected can be a variable, but also know that not all bolts and extractors provide an environment that allows the use of those equally. You can not say across the board that a certain o-ring out performs others. Not all bolts, and especially extractors are made the same.
In a perfect world, we could expect combinations that require no o-ring. Many times that is the case, but this isn't a perfect world.

[rero360]

Here is one for you gentlemen,

Mega Arms MATEN with 18" Select midlength .308 barrel, BCM gas block, CMMG BCG, and DPMS AR10 carbine buffer and spring in normal carbine buffer tube. After a few hundred rounds I started to experience a problem where fresh round would get fed into the chamber but the spent brass would get caught up in the ejection port. I diagnosed it as the gas block had come loose and was moving forward. I put it back into place and locktited it in place. After a couple mags the problem started to happen again but the gas block is still in place.

Ammo is handloaded 175 SMKs at about 2600 fps, loaded to mag length in 10 round M3 pmags. Brass exhibits the slightest of shiny spot from the ejector and a slight impression from the extractor, maybe 5 to 10 thousands of an inch deep on the bottom of the rim.

In doing some reading I have learned that my buffer/tube/spring combo is not the best so I have ordered a VLTOR RE-10 and I have an H3 at home that I can put in it, forgot to order the proper spring for it though, will get it soon.

Is there anything else to consider to be the source of the problem?

[MistWolf]

The stovepipe is the same malfunction as the empty/live round but a with a different hair cut. It's due to weak extraction/ejection. Check your extraction first