Gas key staking and Loctite
- Thread starter strat81
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briansmithwins
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- Aug 1, 2005
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Gas keys get hot and are exposed to solvents. Either one of those things destroys/degrades loctite. Displaced metal also serves as a witness mark that the bolt hasn't moved. BSW
Fast Frank
Member
Man, I see all this talk about gas keys, and I wonder...
How many have actually come loose and stopped the rifle?
How many have actually come loose and stopped the rifle?
That I know of personally? One. Friend of mine's Bushmaster CAR-15 started having problems at a Blackwater carbine class. IIRC, it would cycle when cold, but would become unreliable when the carbine got hot from firing. I guess it was a case of the key being borderline. During the day, the key wouldn't remain stationary when the hot gas attempted to push the carrier back. The key would raise up and enough gas wasn't being directed into the key's opening. IIRC, it caused all sorts of malfunctions and wasn't (at the time) particularly easy to diagnose. FTF. FTE. May have been short stroking as well. (Again, the details are as I recall. I could be misremembering specifics.)
FWIW, that's his patrol carbine. He wasn't too happy about the ordeal. After taking a class with him, I check the key as part of routine maintenance.
Had the key come loose and start smacking the back of the gas tube on my DPMS. Feed jams and the key got dented pretty good. This happened when shooting out in the field, and about 300 miles away from my tools. It was only a $4 replacement part and about 2 minutes to install with a bit of loctite. Lesson learned. Next time it will be staked.
Another hard lesson learned is keeping your chamber nice and clean. The extractor pulled off part of the case head when I fired the first round. My DPMS was my first rifle and I learned quite a bit from it.
W.E.G.
Member
Loctite turns into silly putty at the kind of temps you get on a gas key after just one magazine.
Its just glue!
You gonna trust the integrity of your BOLT CARRIER to glue???
Torque the bolts to correct spec, and stake them according to spec.
Its the only way to be sure.
Its just glue!
You gonna trust the integrity of your BOLT CARRIER to glue???
Torque the bolts to correct spec, and stake them according to spec.
Its the only way to be sure.
Destructo6
Member
Red Loctite melts at 300° f.
Bartholomew Roberts
Member
And for the record, 30 rounds fired semi-auto at 1 second per round (60rpm) will get the external temp of an M4 barrel up to 240F in 30 seconds. So you can hit temps in excess of 300F without working the rifle too hard.
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