Leaky Gas Key

D

Don'tkillbill

New member
Ok I've been have some trouble with short stroking. I replaced my gas rings on the bolt it didn't hurt but the bolt was used hard and I could have done a better job cleaning it.

I replaced the bolt and still issues. I took the carrier and cleaned it good. Like I should have since I got it.

5000-6000 rounds later I have this gas leak. See the attached video.

https://youtu.be/ZNAF1nM_g1c

Those that know this platform what do you think? I guess I need to get the gas key off and see what's up.
 
Broken key bolt is probable. Gas keys should use the spec aviation liquid gasket (Permatex 80019) and have the bolts properly torqued. In that case, no staking is needed.

Staking breaks bolts and was a band-aid "solution" to an assembly problem.

Have rebuilt about a dozen carriers with the same problem. Both of my .450BM gas keys have never been staked.

You can buy a new key, new bolts, Permatex and fix it for about $15.
 
Here is a quote from Mr. Young of Young Manufacturing.

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 8-32 x 1/4" 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.

Good Shooting!

Daniel H Young
President
Click to expand...

The spec is 50-58, and I do stay at the 56 inch-pounds. I have never tried the gel and use the spec liquid gasket I mentioned above.
 
This goes back a long time, but I don't remember anything involving sealer in the Tech manuals. The two mating surfaces were ground and sealed fine. I never saw any "Loose, staked" machine screws either. This was back in the day when everybody was robbing the military blind, before the "Whistle blower" days. I see all these complaints now, and get the idea that half the parts made are now junk.
 
I did surgery and there was some carbon build up and it caused corrosion/gas cutting on the gas key. I salvaged the bolt carrier but the key is not salvageable.

Since it was in the gas key what should I done better to prevent the issue?
 
Gunplummer said:
Buy parts made from better material.
Click to expand...
This. I'm old school, torque to 50 inch pounds, stake. I do like the Brownell's staking tool.

Others I know use Permatex. All seem to work fine and the only guns I see issues with are used for 3-gun competitions. 95% of AR owners will never have enough use to matter.

Jeff

Sent from my XT1254 using Tapatalk
 
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