Looking at building my next AR but I want to do the best I can to reduce extractor vibration.
Do I need a specific type of extractor, spring, or O-ring?
Looking at building my next AR but I want to do the best I can to reduce extractor vibration.
Do I need a specific type of extractor, spring, or O-ring?
I believe KAC has a new bolt with dual ejectors that is specifically designed to mitigate extractor vibration. I can’t speak for anyone else, but extractor vibration has been my biggest issue with the AR-15 platform, and this is a welcome development.
I think the included Viton O-rings, usually tossed in the trash, with new bolts can help reduce the rigorous extractor vibrations.
This. If I had a dollar for every vibrating-extractor based malfunction I’ve had, I’d actually shoot my AR.
Extractor vibration? First time I’ve heard of this. What exactly is that, if you don’t mind me asking?
30 years on the AR, and I’ve never heard of this tragic situation.
Also, KAC’s bolt isn’t new, but it does indeed have dual extractor springs.
The extractor does not vibrate.
It does bounce occasionally. Understanding Extractor Lift in the M16 Family of Weapons
Get a gold colored Colt extractor spring assembly.
They just announced the E3.2 bolt is shipping yesterday.
I don’t keep up with social media so I’m a bit behind the times. But they did say it reduces extractor vibration so I think I will go with an SR15 upper.
E3.2 Bolt. Finally a solution to the vibrating extractor problem that’s been plaguing just all these years.

The revised it?
We shoot Pappabears “Jack Leuba” SR15 almost every week. Awesome gun. But for parts commonality, I’d really lean towards the standard bolt. Not that bolt breakage is a big issue with either design, but my conservative side likes to stay on the beaten path most of the time.
^^^
I’ve never heard of extractor vibration. I’ve not seen any info on this or what the symptoms are. My guess is that its a way to sell special bolts to solve a problem that doesn’t exist, or is minor and only seen in full auto.
This is right, the LMT enhanced also has two extractor springs. But I don’t know that its really necessary. I keep an extra bolt and cam pin with me instead of buying enhanced bolts.
Seems like a lot of people have come out with “enhanced” BCGs. Most have faded away because they didn’t live up to the hype. I don’t know jack about KAC BCGs, but LMT seems legit. The Geissele REBCG (C158 FORGED bolt) has not been around long enough to tell. Others meh…
I do have a couple LMT enhanced BCGs, but I mostly just keep extra BCM bolts with me. I’m not shooting nearly as much as I was anyway, but it seems to me that an extra complete BCG, or extra bolts are the way to go.
^^ Dual extractor springs? Or dual ejectors like some 308 bolts? Please describe extractor vibration and its symptoms. And does this induce a material failure or performance failure that must be cleared? Thanks for your help.
As long as they don’t do harm… whatever. I’ve kinda been sitting on the sideline waiting to see if any issues come up with the modified cam pin tracks… So far nothing negative seems to be happening.
I’ve got quite a few rounds on a pair of LMT E-BCGs, and I can confirm that nothing negative happens. The cam pin does get accelerated wear early on, which seems to plateau and stop. Dudes that clean their guns more routinely might experience this less. I’ve not broken a cam pin or a bolt with those, so its probably a non-issue unless you’re the type of OCD guy that takes the trigger out of his gun every month to deep-clean. I have replaced cam pins prophylactically, as I have done with regular BCGs, but its been a long while and more (hot) rounds than most will shoot in many years. At this point, I’ve taken up the policy that if I don’t take the BCG apart, I won’t notice, therefore wear doesn’t exist. Like any other BCG, I make a point to put a drop of oil on the cam pin anytime I take the BCG out of the gun, because that is what I was taught two decades ago.
TLDR: its fine
Sounds like the “industry” has run out of bottles of snake oil. On a related note, I have a limited supply of extractor-vibration detection sensors, devices, complete kits available for a hefty sum. Single run. Only while supplies last.
bamashooter is the first one in this thread to “get it.”
[smirking emoji]
Who needs KAC? I just installed a Sprinco 5 coil spring and 2 viton o-rings in all my bolts. Wonder if I should have gone with a nested 308 spring setup and a couple o-rings instead…
Extractor vibration?
Your focus should be on grip screws if you want a decent build.
Anything less than OEM Colt grip screws and that shit won’t run.
Extractor vibration?
Your focus should be on greasing up your extractor if you want a decent build.
lol, you SOTAR SNOBS crack me up, anything less than dunking your BCG in a quart jar full of oil and that shit won’t run!
Exactly. It’s when the extractor vibrates.