Something many might not be paying attention to regarding extractors

[LRRPF52]

A good friend of mine, along with several of his friends and family, have been experiencing extractor failures at about 1000rds shooting mostly 16” MLGS Grendels.

I think they’ve broken 6 of them now across at least 3 different rifles.

I asked if they had the O Rings installed, and they all did.

As a rule, I never let one of those O rings near my bolts because they increase the extractor tension too much, placing undue stress on the lip as the bolt goes into battery.

The O rings were meant as a band-aid to address Failure To Extract on 5.56 M4A1s with the KAC QD suppressor, which caused the cyclic rate to increase outside of the optimum window of operation.

Another buddy of mine using JP Bolts has shot over 8700 rounds through a 12.5” Grendel, all of it suppressed, with the Hk PDW buffer kit. No failures.

I’ve been shooting multiple Grendels since 2009, and have never seen an extractor or bolt failure on any of my rifles.

Again, none of them have that O ring in them. I break down all my bolts before installing them, and I can tell even without disassembly if they have that O ring around the extractor spring.

Extraction should be approached from gas system set-up first, then all you need is mild tension and you will have plenty of extraction strength once the case has de-obturated off the chamber walls. Guess how many failure-to-extract issues I’ve had with 6.5 Grendel? I haven’t.

Take this out:


Funny side note. The article I got that image from says you need the O ring or Defender (I have several samples of both sitting in bins that won’t go into my rifles.)

The claim is that the AR-15 has been under-extractored from the start. Millions of rounds of full auto 5.56 say otherwise.

The M16 is one of the most well-behaved rifles I’ve ever shot in automatic mode. With the correct gas system configuration, it runs very well.

[montana]

A good friend of mine, along with several of his friends and family, have been experiencing extractor failures at about 1000rds shooting mostly 16” MLGS Grendels.

I think they’ve broken 6 of them now across at least 3 different rifles.

I asked if they had the O Rings installed, and they all did.

As a rule, I never let one of those O rings near my bolts because they increase the extractor tension too much, placing undue stress on the lip as the bolt goes into battery.

The O rings were meant as a band-aid to address Failure To Extract on 5.56 M4A1s with the KAC QD suppressor, which caused the cyclic rate to increase outside of the optimum window of operation.

Another buddy of mine using JP Bolts has shot over 8700 rounds through a 12.5” Grendel, all of it suppressed, with the Hk PDW buffer kit. No failures.

I’ve been shooting multiple Grendels since 2009, and have never seen an extractor or bolt failure on any of my rifles.

Again, none of them have that O ring in them. I break down all my bolts before installing them, and I can tell even without disassembly if they have that O ring around the extractor spring.

Extraction should be approached from gas system set-up first, then all you need is mild tension and you will have plenty of extraction strength once the case has de-obturated off the chamber walls. Guess how many failure-to-extract issues I’ve had with 6.5 Grendel? I haven’t.

Take this out:


Funny side note. The article I got that image from says you need the O ring or Defender (I have several samples of both sitting in bins that won’t go into my rifles.)

The claim is that the AR-15 has been under-extractored from the start. Millions of rounds of full auto 5.56 say otherwise.

The M16 is one of the most well-behaved rifles I’ve ever shot in automatic mode. With the correct gas system configuration, it runs very well.

Have you tried the Sprinco 5 coil extractor spring in any of your Grendels?

[37L1]

Thanks for that good information.
I've got some bolts that need attention now.

[BehindEnemyLines]

Thanks for the heads up. I checked all mine and none had an O ring.

[PVBoom]

First thing I did after reading an earlier post by LRRPF52 on this was to remove those o-rings from my grendel bolts.

Of course I didn't read that until a week after I had ordered BCM extractor upgrade kits with springs and .. o-rings.

I should double check all my AR bolts and do this. I am half tempted to order an extractor removal tool to ease removal and installation of the roll pins.

[Klem]

I am half tempted to order an extractor removal tool to ease removal and installation of the roll pins.

Or an old case cut in half and a bench vise.

[LRRPF52]

Have you tried the Sprinco 5 coil extractor spring in any of your Grendels?

Nope. Just standard extractor springs with the buffer insert. Somehow, my guns just run. I’m not talking about a single sample size with a few range sessions either.

We’re talking 22” RLGS, multiple 20” guns I’ve built for people, multiple 18” that I own and have built, multiple 16” AA MLGS fluted builds, multiple 16” Liljas, and 12” CLGS suppressed.

All this dating back to 2009.

[LRRPF52]

First thing I did after reading an earlier post by LRRPF52 on this was to remove those o-rings from my grendel bolts.

Of course I didn't read that until a week after I had ordered BCM extractor upgrade kits with springs and .. o-rings.

I should double check all my AR bolts and do this. I am half tempted to order an extractor removal tool to ease removal and installation of the roll pins.

Did you mean ejector removal tool?

Extractors come out with the firing pin or a punch pushing the extractor pin out with ease, unless you have the O ring. Then it will really be stiff and difficult to remove due to the insane amount of extractor tension created by that combination.

[tdbru]

Klem,
how's that work? cut in half how? i assume perpendicular to the opening and not longitudinally ?? how is one using the bench vise? looks like i need to go take some o-rings out.
thanks,
-tdbru

[tdbru]

i can see how using a case and a vice for an ejector removal tool would work. can't figure out how that's going to help with extractor removal though.
-tdbru

[Klem]

Does the same job as the bought one - frees both hands up. Also you don't lose the ejector as you slowly unscrew the vise.

[ATTACH=CONFIG]17226[/ATTACH]

There are two cut cases in the photo. The thin Grendel one, on the left is flush with the bolt face so in the vise there's less chance it rotates whiel you are bashing pins out. The other .223 case is cut further up the case, as you rightly pointed out only does the ejector.

If all you are doing is the extractor, you don't even need a cut case. A vise done up real tight will hold it still while you tap the pin out.

[D.Davis]

FYI I have gone to a 40 S&W case.

[tdbru]

LRRPF52, Klem,
thanks for the heads up. have take the little "o" ring off of the extractor spring. i actually just held the bolt in my hand pinched down on the extractor at the pivot region and pushed the pin out with a pin punch in my other hand. went back together just as easily once the "o" ring was off the extractor spring. i noticed that there was a little rubber cylinder on the inside of the extractor spring as well. i left that rubber cylinder inside the extractor spring when re-assembling the extractor. but the "o" ring is now in a parts drawer. hopefully that will prevent me from having any extractor issues at all.
thanks,
-tdbru

[The Profit Joseph Sith]

well hello again everyone, my extended hiatus is over i guess. time for this recluse to resurface just in time for me to disappear when sniff and blow get into office.
anyway.

Nope. Just standard extractor springs with the buffer insert.

hey good info. thanks for posting.
2 questions:
1. just making sure, but the "buffer" you are referring to is the little mouse turd that goes inside the spring correct?
2. do you find this is universally true with ALL AR caliber variants?
TIA.