Gas Key Loosening?

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Posted: 8/25/2017 9:26:13 PM EDT

Noticed that after ~2,000 rounds on my APF Armory BCG, the gas key has a bit of wiggle in it.

How much of an issue is this? Keep shooting until major wiggles or failure? Replace the whole BCG, just the key, or just re-tighten and re-stake? Something else? Haven't had or known someone this happened to before.

Posted: 8/25/2017 10:11:28 PM EDT

[#1]

If I'm not mistaken it needs to have a type of Loctite sealant between the key and carrier so I don't know if just tightening will be the best. It may work but I'd send it to maybe Adco or someone similar to have it properly reattached.

Posted: 8/25/2017 10:16:55 PM EDT

[#2]

One of my good friends is a gunsmith, so if it just needs a bit of a rebuild then I'll pass it off to him. Just not sure if that's even necessary, or if that's not near enough.

Posted: 8/25/2017 10:47:07 PM EDT

[#3]

Don't just leave it as-is. A loose gas key is never good.

I'd just retighten and then re-stake.

Posted: 8/25/2017 11:41:17 PM EDT

[#4]

Quote History

Quoted:
Don't just leave it as-is. A loose gas key is never good.

I'd just retighten and then re-stake.

View Quote

Sounds good, I'll drop it off with my friend! I really ought to get a vice and punches...but that'd require cleaning my garage to fit a workbench in there.

Posted: 8/26/2017 8:56:20 AM EDT

[#5]

Quote History

Quoted:
If I'm not mistaken it needs to have a type of Loctite sealant between the key and carrier so I don't know if just tightening will be the best. It may work but I'd send it to maybe Adco or someone similar to have it properly reattached.

View Quote

There is no thread locker used in the gas key, just some Form-A- Seal liquid.

Loose keys usually mean a cracked bolt.

Posted: 8/26/2017 11:19:38 AM EDT

[#6]

Quote History

Quoted:

Loose keys usually mean a cracked bolt.

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Is this somethign that will be obvious to see, or no? Where should I look?

Posted: 8/26/2017 11:24:43 AM EDT

[#7]

Quote History

Quoted:

.

Loose keys usually mean a cracked bolt.

View Quote

No it does not.

OP

Was the gas key even staked to begin with?

If it was contact the manufacturer for possible warranty.

Posted: 8/26/2017 11:54:04 AM EDT

[#8]

Tighten and restake.

Posted: 8/26/2017 1:48:14 PM EDT

[#9]

Update: ran it by my friend (gunsmith) and after looking at it he recommended replacement. Said it could probably be put back on, but likely wasn't worth the trouble. Walked out with an Aero NiB and 3 Lancer mags.

Now I just need to figure out what to do with my old BCG.

Posted: 8/26/2017 2:44:29 PM EDT

[#10]

Quote History

Quoted:
Update: ran it by my friend (gunsmith) and after looking at it he recommended replacement. Said it could probably be put back on, but likely wasn't worth the trouble. Walked out with an Aero NiB and 3 Lancer mags.

Now I just need to figure out what to do with my old BCG.

View Quote

I'll take good care of it

I've had two carriers where the gas key came loose. One where I simply had to retighten and stake and the other I had to extract the broken screw. At most you needed new screws I'm betting.

Saying the BCG needs replaced is just silly when every part is available. I'm curious why he said it had to be.

Posted: 8/26/2017 3:33:48 PM EDT

[#11]

Quote History

Quoted:

I'll take good care of it

I've had two carriers where the gas key came loose. One where I simply had to retighten and stake and the other I had to extract the broken screw. At most you needed new screws I'm betting.

Saying the BCG needs replaced is just silly when every part is available. I'm curious why he said it had to be.

View Quote

He said it didn't have to be - but occasionally there's be trouble getting a new one to seat properly. For me and this rifle I'd rather just throw a new BCG in there than save a bit if money and question my parts.

But hell, if you're interested in picking up my old one send me a pm. I don't have a second AR to throw it into anyways.

Posted: 8/29/2017 8:47:44 AM EDT

[#12]

A fool and his money comes to mind.

at most you needed 2 mil-spec screws, T to spec and stake in place. no sealant or loctite required.

Posted: 8/29/2017 12:00:44 PM EDT

[#13]

Quote History

Quoted:

No it does not.

OP

Was the gas key even staked to begin with?

If it was contact the manufacturer for possible warranty.

View Quote

USUALLY

There are more reports of cracked screws versus screws that have loosened up.

Posted: 9/4/2017 1:23:28 PM EDT

[#14]

Replacing gas keys is not a big deal.
I have bought my carriers stripped on occasion.
A touch of aviation form-a-gasket, screws rated for 55 in/lbs, torque and stake.

Posted: 9/4/2017 1:35:00 PM EDT

[#15]

I made a how to awhile back. Feel free to IM with any questions.

https://www.ar15.com/forums/ar-15/How_to_fix_a_loose_gas_key___with_pictures/4-697684/

Posted: 9/6/2017 5:17:31 PM EDT

[#16]

Quoted:
How much of an issue is this?

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At this point, let's assume the best.

But, since you do have a failure, an inspection is warranted. I suggest you field strip the rifle, remove the bolt carrier group, strip it down and clean the parts so any problems are not obscured by dirt. Conduct a thorough visual inspection for abnormal wear and tear, cracking or breakage.

Correct any problems you find. Depending on the problem, you may need to involve a gunsmith or you may need to return the rifle to the manufacturer.

You may even choose to return the rifle to the manufacturer to have them handle fixing this issue if you can bear to be parted from your gun for the time it would take.

re-tighten and re-stake?

View Quote

If you don't find any problems with the components of the bolt carrier group and you want to make the repair on your own, then re-tighten and re-stake the bolts, put the bolt carrier group back together and enjoy your rifle.

Reinspect the rifle after another hundred or so rounds to make sure your repair is correct.

Posted: 9/6/2017 5:49:41 PM EDT

[#17]

Quote History

Quoted:

Is this somethign that will be obvious to see, or no? Where should I look?

View Quote

No.

Usually, if cracked, it will be between the head and the shank.

If a screw is loose, ask yourself, "if it was tight once, why did it loosen up?"

1) it rotated - if it was staked even to the slightest degree, this is unlikely.
2) the bolt got longer, it stretched or broke.
3) the key got shorter - something was under the key when it was originally torqued that it not there now, dirt, a burr or something of that nature, that has gone away.

In any case, I would inspect the key off the carrier and replace the screws, re-stake and carry on. whether that is something you feel you can handle is up to you.

Posted: 9/8/2017 8:08:41 AM EDT

[#18]

Quote History

Quoted:
I made a how to awhile back. Feel free to IM with any questions.

https://www.ar15.com/forums/ar-15/How_to_fix_a_loose_gas_key___with_pictures/4-697684/

View Quote

Hm, that doesn't look to bad! But by the time I got the chemicals and an in/lb wrench, I'd be a good ways to the cost of a BCG anyways. I'll just run with the Aero replacement for now, but I'll keep the old APF around. At some point I'll get around to fixing it and keep it on hand as a spare.

Posted: 9/8/2017 9:20:53 AM EDT

[#19]

Where are you at in TX? If your east of DFW you might be able to drop it off with me sometime and I could knock it out for you.

Posted: 9/9/2017 6:42:53 AM EDT

[#20]

I just replaced one. I didn't have any sealant at the time. I used LOW strength loctite for the sealant. Staked with a center punch and a claw hammer .

Posted: 9/28/2017 11:08:39 PM EDT

[#21]

Quote History

Quoted:
I just replaced one. I didn't have any sealant at the time. I used LOW strength loctite for the sealant. Staked with a center punch and a claw hammer .

View Quote

Most AR builders do not use a sealant, it's part of the TDP. The bottom of the key is LIGHTLY coated with Permatex Aviation Form-A-Gasket #3. You can pick up a can at most auto parts stores for around $5.00 for a small can.

Posted: 9/29/2017 7:49:29 AM EDT

[#22]

Quote History

Quoted:

Most AR builders do not use a sealant, it's part of the TDP. The bottom of the key is LIGHTLY coated with Permatex Aviation Form-A-Gasket #3. You can pick up a can at most auto parts stores for around $5.00 for a small can.

View Quote

Yet the Army technical maintenance manual does not call for any sealant . . .

So, any arsenal rework won't have any.

Posted: 9/30/2017 10:34:41 AM EDT

[#23]

Quote History

Quoted:

Yet the Army technical maintenance manual does not call for any sealant . . .

So, any arsenal rework won't have any.

View Quote

Colt manual I read only calls for a very small amount around the gas hole of the key but not enough to get into the gas hole in the carrier.
I have purchased carriers from a couple different places that had different kinds of goop completely under the key. When I pulled the keys off the new carriers the goop had only cured out partially under the edges and was still wet under the rest. One looked like a gasket sealant and the other two looked like a thread locker. I pulled them to clean them off when I saw the goop around edges of the key and at the screw bottoms in the carrier. One even had some at the gas hole in the carrier.

I have taken a few keys off that had the sealant ring around the gas port hole in the key and carrier but it was just a very small circle of sealant around the holes.

page 3-2-26 explains where the sealant goes. http://coltcanada.com/assets/10044s-2005-09-20.pdf

Posted: 10/1/2017 9:02:01 PM EDT

[#24]

TM 9-23-329-23 & P, Work Package 0013, Assembly (pg 0013-2). No mention of any sealant (other than a few rounds).

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