BCM BCG in my 6920..

[XM15M4Guy]

Hi all,

I have recently picked up a FDE ion bonded BCG for Bravo Co for my 6920. Unfortunately, I do not own a set of go/no go gauges. I realize it's always a good idea, but should I be concerned about having it checked before shooting using these components?

Thanks

[Eurodriver]

nope.

[SomeOtherGuy]

Hi all,

I have recently picked up a FDE ion bonded BCG for Bravo Co for my 6920. Unfortunately, I do not own a set of go/no go gauges. I realize it's always a good idea, but should I be concerned about having it checked before shooting using these components?
Thanks

Use the original bolt from the 6920, just install it in the BCM carrier (I assume you bought it for the Ionbond benefits) and set aside the BCM bolt as a spare.

You aren't likely to have any headspace issues, but the BCM quality isn't necessarily an upgrade from Colt (I'd rate them about equal, with any advantage to Colt) and you can forget about the mere possibility of a headspace issue by using the original Colt bolt.

[SteveL]

nope.

This.

[XM15M4Guy]

This.

So, If i understand correctly, 'nope" means I'm GTG...right?

[LowSpeed_HighDrag]

So, If i understand correctly, 'nope" means I'm GTG...right?

Yes, you are good. I don't know how many BCG and Bolts I've interchanged between makes and models with no issues.

[tylerw02]

You're fine.

Was something wrong with that Colt BCG?


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[XM15M4Guy]

You're fine.

Was something wrong with that Colt BCG?


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Nothing at all. I picked up the BCM BCG because I needed another one and I liked the FDE coating. Since my 6920 had fde furniture, I thought I would swap it. Either the BCM or the Colt group will go into my first build.

[556BlackRifle]

BCM BCG and Colt Barrel, you should be GTG, however, with lower quality (e.g. chicom junk) you may not be.

[MegademiC]

Use the original bolt from the 6920, just install it in the BCM carrier (I assume you bought it for the Ionbond benefits) and set aside the BCM bolt as a spare.

You aren't likely to have any headspace issues, but the BCM quality isn't necessarily an upgrade from Colt (I'd rate them about equal, with any advantage to Colt) and you can forget about the mere possibility of a headspace issue by using the original Colt bolt.

This.
If you want the loo, swap the carriers and keep the bolt with each gun. It probably won't matter, but it erases all doubt.

[Stickman]

I dropped a new bolt in with a barrel the other day, both known good components from good companies. Guess what? THEY DID NOT FUNCTION PROPERLY.

Lots of people like to say it doesn't matter, but the simple truth is that factually it does matter. The odds are there won't be a problem, but that doesn't mean it won't happen.

[Kdubya]

I dropped a new bolt in with a barrel the other day, both known good components from good companies. Guess what? THEY DID NOT FUNCTION PROPERLY.

Lots of people like to say it doesn't matter, but the simple truth is that factually it does matter. The odds are there won't be a problem, but that doesn't mean it won't happen.

Absolutely agree. No rifle or component, from any company, can be christened GTG until it's actually been verified. Preferably with at least a few hundred rounds if it might be pressed into defensive service.

However, in the context of this thread, was it actually a headspacing issue that you'd encountered? I've seen plenty of examples with known brands that experienced issues out of the box with FTEs and FTFs. But, reports of problems with headspacing seem to be exceedingly rare. My go-to gunsmith sees quite a few ARs come through his shop. Recently I had him check the headspacing on a new rifle, and he remarked about not being able to even remember the last time he'd come across a rifle that didn't pass the gauge tests.

[ccosby]

I dropped a new bolt in with a barrel the other day, both known good components from good companies. Guess what? THEY DID NOT FUNCTION PROPERLY.

Lots of people like to say it doesn't matter, but the simple truth is that factually it does matter. The odds are there won't be a problem, but that doesn't mean it won't happen.

The key is that odds are you will be fine. Ideally it is best to check headspace on the bolt. I'd personally leave the colt bolt in the gun and just swap carriers if I didn't have headspace gauges to check.

Edit: I can't think of the last time I've personally seen headspace issues with quality parts(new) although I'm not an armor. I've just helped multiple friends with their guns. I'm sure someone that is a gunsmith would see it far more often although even then I'm guessing most are fine.

[ScottsBad]

Everyone says they're GTG without checking the head space, but I'm just kind of weird about these things. I don't worry as much about BCM with BCM (I guess I should), but most of the time I just use a 'Colt Field Gauge' (Brownnell's sells them) to check that what ever I'm putting together is not too sloppy. I makes me feel better anyway.

[Cobrasks]

I had a similar concern a while back .

I have a Colt 6920 that had a tiny hole develop on the flat
part of the bolt face between the firing pin hole and the bolt lugs .

It wasn't all the way through but it was definitely noticeable .
It looked like there almost had to have been an air pocket or something
in it when it was made . It didn't appear to be corroded out .
It wasn't originally there so I wonder if perhaps the coating filled the
hole and came out after use .
It was past Colt's 1 year warranty at that time so I bought a BCM
bolt and threw it in there .

I researched and at the time everyone said that was OK .

Maybe that sounds OCD to replace it but for $65 I thought it was better
safe then to loose a digit or an eye .

[georgeib]

I had a similar concern a while back .

I have a Colt 6920 that had a tiny hole develop on the flat
part of the bolt face between the firing pin hole and the bolt lugs .

It wasn't all the way through but it was definitely noticeable .
It looked like there almost had to have been an air pocket or something
in it when it was made . It didn't appear to be corroded out .
It wasn't originally there so I wonder if perhaps the coating filled the
hole and came out after use .
It was past Colt's 1 year warranty at that time so I bought a BCM
bolt and threw it in there .

I researched and at the time everyone said that was OK .

Maybe that sounds OCD to replace it but for $65 I thought it was better
safe then to loose a digit or an eye .

I thought that Colt bolts were supposed to be MPI inspected. Sure doesn't look like your's was.

[Kdubya]

I thought that Colt bolts were supposed to be MPI inspected. Sure doesn't look like your's was.

MPI only matters if the person doing the testing catches the flaw. And that's assuming it was actually present during the test.

What I'm more surprised with is that everyone told him it was OK. Is a hole developing in the bolt face so common that it's been proven to be of little consequence?