Staking Gas Keys

[HammerheadSSN663]

I've read all the internet posts on what companys stake, which ones are lousy at it, and which ones don't even bother.

My question is why stake? If its so important to mechanically gouge the metal after the key is inserted then why not just make a hex screw that doesn't back out in the first place? Or better yet, why even have keys in the first place? Just make the bolt one solid piece of metal(?)

Also, once its staked, what if you need to remove the hex screw? (Now you can't cause its staked!)

Shouldn't tightening the keys (with proper torgue) be part of regular maintenance? And if so, the whole gas key backing out thing is moot correct?

I'm getting the feeling that if it was/is so important than all the company's would stake and/or recall those firearms that were not (staked).

Seems everyone is obsessed with staking to the point that since my BMs aren't 'proplerly' staked I should put them out in Mondays trash and go buy a 'real' AR 15 like Colt, BCM, or LMT.

just wondering folks.

 

[Tommygunn]

Actually, tightening the keys with proper torque is part of assembly process. Properly staking them assures that they won't back out.
Remember you have mechanical stress on the bolt carrier, plus as it heats up metal expands and then as it cools it contracts.
These cycles might tend to loosen the keys. It helps to properly maintain them, but to be sure the last time I heard about a failure of the gaskey it was in a Colt being used by a soldier in Iraq, and those are supposed to be mil spec -- you know, the "cream of the crop," "the holy grail" of ARs.
Nevertheless, the key does need to be properly staked and some companies don't; there are tools available to properly stake them available over the net.
As far as making the gaskey part of the bolt carrier, that would probably be too expensive and complex of an operation. I don't know how they could make one that doesn't back out. Could be, but might just add expense. Plus how would it effect repairs?
Just because your BM ("Bushmaster"??) might not be correctly staked doesn't mean it is junk. As I said you could acquire that tool and stake it. Some gunsmiths could do it for a charge. I know a number of people with Bushies that are happy with them so don't go all panicky. And, remember what I said above about that one key that did loosen being on a Colt? Even the best guns have problems. There is no "magic gun." Even good ones can have troubles.

 

[briansmithwins]

Well, I would agree that BMs aren't the best ARs, and staking is only one of corners they cut.

Staking lets the part be made at a cheaper cost and allows for repairs if the relatively delicate gas key is dented or otherwise damaged. The M16 armorer's manual I have calls for the staking to be ground off with a bench grinder if the key needs to be removed for replacement.

Given the environment the BCG lives in, displacing some metal is a very good way of ensuring the bolts don't back out.

BSW

 

[taliv]

seems like if you'd "read all the internet posts" you'd have read the answer to your question at least a thousand times over.

so what part is it you really don't understand?

if you feel there is some proper torque pressure that would ensure screws don't back out, i'd encourage you to call bushamster and let them know. perhaps they can save an extra few bucks by skipping their faux staking process and have a more reliable gun.

 

[SentinelStrategic]

Bushmaster is under the same umbrella and parts chain as DPMS and Remington, and they all have notable consistent issues with improper gas key staking. I have a gas key staking tool and file set on-hand at every training course for that exact reason. It's a simple 3 minute fix and nothing to worry about so long as there are no issues with the gas key and screws.
The gas key and screws are designed to be kept on the BCG, and if removed, they're to be discarded and replaced with a new one. They're not reusable. They're also inexpensive, so it's not a big issue. People make a bigger deal out of replacing parts on ARs than they need to. The AR is a machine, and like any other machine or engine, they require maintenance and replacement of worn parts.

Simply put, staking the gas key is a measure for increasing reliability. It's not something you need to get bent out of shape about. I think maybe you are over-thinking the matter. If they had found a better way to do it, I'm sure they would have done something to the rifle in the past 40 years to correct it...but they haven't because there's been no need to.

 

[DenaliPark]

I've read all the internet posts on what companys stake, which ones are lousy at it, and which ones don't even bother.

My question is why stake? If its so important to mechanically gouge the metal after the key is inserted then why not just make a hex screw that doesn't back out in the first place? Or better yet, why even have keys in the first place? Just make the bolt one solid piece of metal(?)

Also, once its staked, what if you need to remove the hex screw? (Now you can't cause its staked!)

Shouldn't tightening the keys (with proper torgue) be part of regular maintenance? And if so, the whole gas key backing out thing is moot correct?

I'm getting the feeling that if it was/is so important than all the company's would stake and/or recall those firearms that were not (staked).

Seems everyone is obsessed with staking to the point that since my BMs aren't 'proplerly' staked I should put them out in Mondays trash and go buy a 'real' AR 15 like Colt, BCM, or LMT.

just wondering folks.

It's pretty simple, if all you're doing is punching paper, then you're not likely to have any issues, however if you're actually going to be relying on the weapon for professional deployments, then staking is essential in maintaining combat reliability.

As for your Bushmaster, why be chincy, just replace their crappy bolt with a BCM or DD full auto BCG for about $120.00 - $150.00 and be done with it. Replace that BCG and your Bushy will be just fine...

 

[madcratebuilder]

Bushmaster is under the same umbrella and parts chain as DPMS and Remington, and they all have notable consistent issues with improper gas key staking. I have a gas key staking tool and file set on-hand at every training course for that exact reason. It's a simple 3 minute fix and nothing to worry about so long as there are no issues with the gas key and screws.
The gas key and screws are designed to be kept on the BCG, and if removed, they're to be discarded and replaced with a new one. They're not reusable. They're also inexpensive, so it's not a big issue. People make a bigger deal out of replacing parts on ARs than they need to. The AR is a machine, and like any other machine or engine, they require maintenance and replacement of worn parts.

Simply put, staking the gas key is a measure for increasing reliability. It's not something you need to get bent out of shape about. I think maybe you are over-thinking the matter. If they had found a better way to do it, I'm sure they would have done something to the rifle in the past 40 years to correct it...but they haven't because there's been no need to.

+1000

From the 23&P

NOTE
Do not reuse old carrier and key screws
New carrier and key screws must be
used at assembly

Never retorque carrier screws, replace them. Carrier key inspection should be part of your regular PM.

Young Manufacturing makes some of the best AR parts you can buy, this is what they say about carrier screw stacking.

Staking the gas key on the AR-15 and M-16 carrier.

There has been a lot of talk about the pros and cons of staking the gas key on the carrier. Here is our opinion and why Young Manufacturing will not stake keys. We have been making carriers since 1991. The US Mil Spec. assembly drawing requires the carrier key to be staked. Contrary to some popular opinions staking does not “SEAL” the gas key. Staking keeps the screws from backing out Period. If you do not properly torque the screws to 56 inch pounds you will be staking a screw that is loose or one that is over torqued and prone to breakage. We have seen plenty of staked screws that are loose or broken. The Mil Spec. also calls for the gas key bottom surface to be “SEALED” with Permatex gasket sealer. Something no one does to our knowledge. Here is our procedure for installing a gas key. First clean the oil from the gas key and the mating surface on the carrier. Then clean the oil from the screw threads. We use break cleaner for this. Next use a very light coating of Permatex high strength thread locker gel on the bottom of the key. PN 27010. This is much easier to use than the Permatex gasket sealer. It comes in a plastic twist dispenser. Make sure you don’t use so much that it squishes into the gas port hole. The cure rate is 60 minutes. Next coat the screw threads with the same gel. Install the key and torque the screws to 56 inch pounds. Should you decide to remove the key for some reason don’t use the old screws when you put the key back on! You will most likely break them during installation or when you fire the rifle. Go to the local hardware store and buy new 10-32 x ¼” SHCS. If you feel the need to stake the screws spend the money and get one of the staking tools from Brownell that uses a screw type system to swedge the material into the top of the screw. Don’t use a hammer and a punch! You can stretch the thread on the screw and now you have a loose screw that will eventually break if the gun even fires. We will not warrantee a carrier with a staked key no matter who staked it. You will be charged for a new key and any labor required to remove broken screws.

Broken or loose carrier key screws are caused by improper assemble, reusing used screws and/or poor PM. I've been shooting Colt, ArmaLite and Bushmaster for well over thirty years and I've had one screw break on a ArmaLite. That was repaired during PM before there was a malfunction.

 

[Bartholomew Roberts]

My question is why stake? If its so important to mechanically gouge the metal after the key is inserted then why not just make a hex screw that doesn't back out in the first place? Or better yet, why even have keys in the first place? Just make the bolt one solid piece of metal(?)

It is staked so the screws do not back out, which isn't uncommon on a rifle due to extremes of temperature and constant vibration from shooting/bumping around in a vehicle. I could spend about 5 minutes just listing the threaded parts I've personally had this happen too.

It isn't made that way because carving a channel for gas through a milled gas key would be a delicate and expensive operation. Not to mention, you do get the occasional popped primer crushed into the gas key and being able to remove the gas key can be handy.

Also, once its staked, what if you need to remove the hex screw? (Now you can't cause its staked!)

You can remove a staked gas key. It makes it more difficult for the screw to back out in normal use, not impossible to undo.

Shouldn't tightening the keys (with proper torgue) be part of regular maintenance? And if so, the whole gas key backing out thing is moot correct?

If you pack the first chute right, there isn't much need for a second one; but they still remain a popular accessory for some reason.

 

[TonyAngel]

I see staking as just a bit of insurance. The fact of the matter is that fasteners come loose, whether they were properly torqued or not. It can happen on anything mechanical.

 

[Kwanger]

I see staking as just a bit of insurance. The fact of the matter is that fasteners come loose, whether they were properly torqued or not. It can happen on anything mechanical.

That's exactly it; nothing more, nothing less.