Cold Weather BCG failure?

[Doc Safari]

Never heard of this before, but here is an apparent BCG failure due to sub-freezing weather:

http://www.ar15.com/forums/t_3_118/557141_BCM_cold_weather_failure__BCG____Public_Service_Announcement.html

My take on this is that somehow the o-ring hardened due to the cold, becoming less flexible and therefore interfering with the normal pivot/flex/chambering operation of the extractor.

I think it would be highly unlikely that the dimensions of hardened steel BCG components would be changing due to the cold.

[Clint]

O-rings and HD springs are not recommended together anyhow.

Use HD spring + insert or STD spring + insert + O-ring.

O-rings ( and everything else for that matter ) harden up as temperature drops.

The mil-spec viton orings are rated for dynamic seal service down to -15F.

As an extractor spring, they probably need to be a little more flexible than that. They have a low temperature TR-10 rating of 5F.

That is probably the lowest service temp suitable for it as a spring.

If you plan to operate in the arctic, the o-ring would not be recommended.

[Iraqgunz]

For all of those who want to know why we have a policy of contacting the manufacturer first- you needn't look further than this thread.

1. Why is the idiot using an O-ring on a 16" barrel? It's not necessary and in fact I wouldn't use an O-ring except in very limited circumstances.

2. He says it wasn't the O-ring completely, but as I read it, the O-ring was the only issue.

The peanut gallery then chimes in and makes assumptions. IMO Bravo Company took a hit needlessly because of some twit who probably has little understanding of the weapon. Notice that the OP also essentially calls Paul a liar when he says that the O-ring was already installed into the BCG.

[kwelz]

Yep IG....
Threads like that are why I am frequenting other boards less and less.

[Belmont31R]

The BCM Extractor Spring is so strong the Mil-Spec Crane O-Ring will probably not be needed, but it is included.

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm

[Ironman8]

Since this thread is already here I won't make my own, but this has been something that I've been wanting to ask for a while now...

When is an O-ring needed?
When is an insert needed?
All these do is increase extractor tension, correct?
What are the "symptoms" that point to the "need" for these items?
Is there such thing as "overkill" if all the components are used at the same time?

I have a standard bolt that came with my Noveske 14.5" carbine and has the spring, blue insert, AND O-ring. I've never had an extraction problem, ever. But it would seem from what I have read, that the O-ring isn't necessary.

Any thoughts?

[5pins]

Since this thread is already here I won't make my own, but this has been something that I've been wanting to ask for a while now...

When is an O-ring needed?
When is an insert needed?
All these do is increase extractor tension, correct?
What are the "symptoms" that point to the "need" for these items?
Is there such thing as "overkill" if all the components are used at the same time?

I have a standard bolt that came with my Noveske 14.5" carbine and has the spring, blue insert, AND O-ring. I've never had an extraction problem, ever. But it would seem from what I have read, that the O-ring isn't necessary.

Any thoughts?

Your inset should be black not blue. The blue was for rifles and black for carbines but it has all been standardize to black now. IIRC the O ring was developed for SBR’s

[Iraqgunz]

Every single thing you have asked here has been discussed numerous times.


Since this thread is already here I won't make my own, but this has been something that I've been wanting to ask for a while now...

When is an O-ring needed? They were part of the SOPMOD upgrade program. The specifics have been addressed before. Essentially they are for short uppers.

When is an insert needed? An insert should always be present with the spring.

All these do is increase extractor tension, correct? Yes, which can be too much and cause failures of the extractor to grasp the rim of the cartridge.

What are the "symptoms" that point to the "need" for these items?
Is there such thing as "overkill" if all the components are used at the same time? Yes, as answered above.

I have a standard bolt that came with my Noveske 14.5" carbine and has the spring, blue insert, AND O-ring. I've never had an extraction problem, ever. But it would seem from what I have read, that the O-ring isn't necessary. Correct. I would simply get a new Colt copper colored spring with black insert.

Any thoughts?

[Univibe]

I'm getting ready to order a bunch of spare parts from BCM, including extractor springs. They include inserts and o-rings with the springs.

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20%203pack.htmhttp://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20%203pack.htm

Are y'all saying that on my 20" and 16", I should just put the spring in w/o the insert or o-ring?

[5pins]

I'm getting ready to order a bunch of spare parts from BCM, including extractor springs. They include inserts and o-rings with the springs.

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20%203pack.htmhttp://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20%203pack.htm

Are y'all saying that on my 20" and 16", I should just put the spring in w/o the insert or o-ring?

You need the insert but not the O ring.

[Dionysusigma]

And a 10.5" barrel with a carbine-length gas system should use an o-ring? Especially when suppressed?

[Iraqgunz]

My advice is to use a Colt copper color M4 extractor spring assembly. I am 99.9% certain you will discover that you don't need the O-ring.


And a 10.5" barrel with a carbine-length gas system should use an o-ring? Especially when suppressed?

[C4IGrant]

We sell tons of BCM BCG's and NEVER ONCE have we seen an O-Ring installed. That means that the guy is either lying or bought it from someone that installed it.


C4

[Heavy Metal]

We sell tons of BCM BCG's and NEVER ONCE have we seen an O-Ring installed. That means that the guy is either lying or bought it from someone that installed it.


C4

I even asked him if someone else could have installed it but he seems insistant it was installed at the factory.

I bet he put it on himself, put it away and forgot about it. Too stubborn to admit his **** up.

[BufordTJustice]

I think Heavy has it.

One of the luxuries of the interwebz is that you don't have to admit when you **** something up.

Those are the same people who lie to me at work but can't make eye contact while doing so.

This guy is full of shit....and may even be a self-motivated 'spikes-defender'. I say this as a person who currently uses a spikes complete lower for my HD/patrol carbine.

[Generalpie]

After my next range trip with the team I will be due for a new spring and since I don't have any spares currently I am going exactly this route.

Often simpler is more betterer. Poor grammar but good advice. ;)


My advice is to use a Colt copper color M4 extractor spring assembly. I am 99.9% certain you will discover that you don't need the O-ring.

[TunaFisherman]

I even asked him if someone else could have installed it but he seems insistant it was installed at the factory.

I bet he put it on himself, put it away and forgot about it. Too stubborn to admit his **** up.

I just bought a 16" BCM upper and it came from BCM with the O-ring sealed in a small plastic bag to be installed by the buyer. They dont come installed

[Heavy Metal]

I just bought a 16" BCM upper and it came from BCM with the O-ring sealed in a small plastic bag to be installed by the buyer. They dont come installed


Exactly. He proabally installed it so he could trash the plastic bag.

[C4IGrant]

I even asked him if someone else could have installed it but he seems insistant it was installed at the factory.

I bet he put it on himself, put it away and forgot about it. Too stubborn to admit his **** up.

Ya that is my guess.

For those that have never seen a BCM BCG, the BCG comes SEALED in a bag and at that end of that bag, the O-Ring is sealed in its own compartment.



C4

[Colt-45]

Glad the "this is why AK is better" crowd stayed out of the argument.

[Heavy Metal]

One thing I have noticed is the more popular and more common the AK is, the more ways to **** one up have came onto the market.