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04-13-2020, 10:32 PM
(This post was last modified: 04-15-2020, 08:17 PM by LRRPF52.)
Here we go fellas.
I already went through a few BCA barrels last year before I found a shooter.
A few months ago I picked up a BCA 10.5" heavy profile pistol length gas barrel for 50ish bucks shipped.
Massively overgassed, as I knew it would be.
I fixed the gas issue by putting an insert into the gas block that restricted the flow.
I immediately sheared an extractor.
Now, I should mention that I've previously had to have BCA replace an extractor and the BCG.
They sent me a replacement extractor. I got about 30 rounds out of this one before it sheared as well.
I'm not shooting handloads. I'm shooting Hornady Black, Federal GMM, or Wolf Steel.
I get that Wolf can be hard on extractors, but how common is this?
I just sent in the whole BCG for replacement. In the mean time, I already replaced my Main rifle's BCG with a Toolcraft.
Brass looks fine, no signs of damage or pressure.
Is this just a bunch of extractors that are likely from the same lot and faulty?
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Knowing bca it's possible it's not even a grendel extractor.
Best advice I can give is buy a extractor from Alexander arms and install and adjustable gas block because it sounds like your still very over gassed.
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Slappy,
This sounds extraordinary, how many cheap barrels are we talking about in one year?
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I'm not overgassed. It's a pistol-length gas system. The dummies at BCA drilled the hole 0.12"
I restricted gas to 0.046" and it cycles fine, locks back fine, and is soft-shooting. Ejection is about 4 o'clock when I'm not busy shearing extractors.
Before I restricted gas, it felt about like a 20 gauge shooting slugs when I shot it.
Thanks for the tip about possibly not even sending me a Grendel extractor. That would make sense if that's what they did.
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When does cheap stop being cheap?
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Slappy,
Have you got a photo of the insert, I'm interested in what you've done.
How many barrels in 12 months did you go through? What did they say?
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slappyhooper Wrote:I'm not overgassed. It's a pistol-length gas system. The dummies at BCA drilled the hole 0.12"
I restricted gas to 0.046" and it cycles fine, locks back fine, and is soft-shooting. Ejection is about 4 o'clock when I'm not busy shearing extractors.
Before I restricted gas, it felt about like a 20 gauge shooting slugs when I shot it.
Thanks for the tip about possibly not even sending me a Grendel extractor. That would make sense if that's what they did.
That's probably the issue right there. Carbine length gas is as short as should be used, pistol length is to short and must be too harsh on extracrion.
Honestly I would probably walk away from bca and buy a better made barrel.
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04-14-2020, 01:58 AM
(This post was last modified: 04-14-2020, 02:04 AM by VASCAR2.)
If the receiver face is not square it throws off the alignment of the bolt face to the barrel extension. Curious if you lapped the front of the upper receiver? Another culprit can be a short chamber where the bullet is jammed into the rifling which can spike pressures.
If I really wanted a 10.5 inch 6.5 Grendel pistol I'd buy one of rebby group buy Lilja 6.5 Grendel barrels. BCA has become a very common topic on this forum since they entered the 6.5 Grendel market.
http://www.65grendel.com/forum/showthrea...r-round-2)
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3 2 1 go
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I learned my lesson with BCA after having to send a barrel back.Ill use their parts occasionally. Upper receiver ,handguard,ect...But I will never use a BCA barrel again. For every bad barrel you break in ,youre wasting at least $200 in ammo. Multiply that times several barrels or you couldve bought a quality barrel that guarantees you accuracy.
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All I did was tap the gas hole on my gas block for 10-32 and thread one of these up there.
https://www.mcmaster.com/91979a576
"vented set screw". You can also just make your own, but this was simpler.
It's a little more complicated for nitrided gas blocks. You have to use a diamond bit to get past the surface hardening before you can tap it easily, but it only takes a few seconds.
Thread the vented set screw up there so it's flush with the top of the gas block and call 'er good. If you need to, you can always open it up a little more, but it's a good starting point.
I got the idea from Black River Tactical inserts.
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Receiver face is lapped and the barrel is bedded with .02 stainless shim stock.
Yup, I'm well aware of the BCA reputation. I like messing around with cheap barrels though, which is why I bought this one.
I've just never freaking had so many extractors commit suicide in such short order on me.
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Those shorty Grendels to me look way cool. I'd like one someday but they have their shortcomings so to speak. From what I've read the shorter gas length system is the harder it is on parts. If the bolt is trying to extract before the gas pressure has gone down enough that the brass contracts then it will be very hard on the extractor. An adjustable gas block may be a must have.
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04-14-2020, 06:07 AM
(This post was last modified: 04-14-2020, 06:18 AM by meatsweats.)
Id run a heavier H3 buffer. Thinking its a cheap solution. H2 may work? I run a heavier buffer on my 300 bo pistol.
Adjustable gas block might help.
MS
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slappyhooper Wrote:All I did was tap the gas hole on my gas block for 10-32 and thread one of these up there.
https://www.mcmaster.com/91979a576
"vented set screw". You can also just make your own, but this was simpler.
It's a little more complicated for nitrided gas blocks. You have to use a diamond bit to get past the surface hardening before you can tap it easily, but it only takes a few seconds.
Thread the vented set screw up there so it's flush with the top of the gas block and call 'er good. If you need to, you can always open it up a little more, but it's a good starting point.
I got the idea from Black River Tactical inserts.
That's a cool idea.
If I understand you correctly, like the BRT design you came in from the ID of the gas block (where the barrel sits) and machined a threaded hole that only goes as far as where the gas tube is? So you come in from where one of the clamping grub screws sit on the bottom of the gas tube?
Have you seen their gas tubes with a smaller hole for restricting over-gassed ports; the EZTube tubes? That would work too, but at $50 a tube it makes you wonder whether that money is better spent.
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Correct. That's exactly what I did.
I saw the gas tube, but figured I'd Bubba this and save myself a bit of money.
It's dead simple
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You over paid for the pistol barrel
Theyd of had to given me 50 bucks to use it
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Are you running an O ring or an extra power extractor spring?
In 5.56 too much tension can be harder on extractors.
Id agree with trying a better quality extractor. If theres an o ring, lose it.
Rough chamber could also be an issue, Id give it a bit of polishing.
Also possible the combination of too much gas damaged a weak extractor. Since youve fixed your gas issue, if you break another extractor its gotta be a build issue.
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