AR15 Gas key Damaged

[Maedho12]

Can anyone help me understand what happened to my gas key? These marks were not here 200-300 rounds ago. Gas tube is in good shape and no signs of damage. I recently changed muzzle devices for a suppressor. Rifle functions fine other than the damage shown in the pic.

I'm all ears.

Thank you

 

[Biggie1976]

Key didn’t fit the lock. Sorry just couldn’t help myself.

Unfortunately I have no real opinion to share.

 

[cas6969]

I've seen a blown out primer jammed in a gas key, one of those golden BB, blow up the Death Star one in a millions maybe, but anything can happen.

 

[Rancid Coolaid]

I'm just a dumb Marine, I mostly stick to eating crayons and licking windows; but how sure are you that damage was done while the gun was firing rather than while it was being cleaned or other?
It seems to me that marks like that on the key would leave marks on whatever made them too, unless it was transient debris just passing through your upper receiver. In which case, damn dude, clear your shit better.
Hope it helps...

 

[6.5SH]

I've seen a blown out primer jammed in a gas key, one of those golden BB, blow up the Death Star one in a millions maybe, but anything can happen.

I've seen blown primers scatter the anvil and cups causing intermittent malfunctions. The Frontier brand stuff was bad about it in hot weather.

 

[Hobo Hilton]

Is it possible the marks were there when the weapon was built. Could they have been damaged while shipping parts or from the previous owner of the bolt assembly ?

 

[scott5456]

Does the inside of the charging handle have any damage on the tip? I doubt that would cause it as the handle is typically aluminum and that gas key is steel. I'd take a bunch of aluminum carnage to cause those marks on steel. If no marks on the charging handle or on the inside of the upper receiver, it has to be handling damage. The barrel extension stops the BCG from traveling further due to lock up and the bolt interfacing with the barrel extension.

 

[Boon20]

Bolt over ride?
Or malfunction drills?

 

[UpSideDown]

I've seen blown primers scatter the anvil and cups causing intermittent malfunctions. The Frontier brand stuff was bad about it in hot weather.

Interesting you mention that. I have a gut feeling that the powder in Frontier is very temperature sensitive. I noticed if I got a gun hot with high round count and let the round sit in the chamber before firing it was noticeably 'hot' on firing, as in overpressure. I talked with my local gun shop about it and they said they've had two guns explode while running Frontier but it wasn't certain it was the ammo. I won't touch the stuff anymore.

 

[elwarpo]

You said suppressor, so the suppressor will overgas it and the bolt will go both directions with much more force, posssibly causing the damage.

 

[UpSideDown]

You said suppressor, so the suppressor will overgas it and the bolt will go both directions with much more force, posssibly causing the damage.

That gas key had to hit something though. The bolt is what takes the forward force.

 

[Evintos]

Possible when firing in an over gassed suppressor situation, high BCG velocity, combined with barrel whip, a slight misalignment of the gas key and gas tube resulted in damage from gas key/gas tube impact.

Force = Mass x Acceleration.

Look up pictures of gas key or carrier key gas tube damage, detented gas key, or other similar key words and you'll see some what similar images or even worse.

The fix - ensure that the gas block and gas tube are aligned properly. Ensure that the gas key is torqued on straight on your bolt carrier with 50-58 in/lb.

 

[RTH1800]

I have had some bad lots of Hornady ammo they blew primers every shot in every .223 I fired it in. Hornady told me basically they don’t give a shit. “It’s just your rifles which are not chambered correctly.”

All of them I suppose.

I could see a blown primer causing that damage.

 

[DeathBeforeDismount]

Yea it happens and its a bit expensive to fix correctly. You will want a new gas key, Colts are the gold standard and about $30-50 for the Key. You want new fastners and a staking tool such as the MOACKS. The 2 is the easier and most reliable. Their OACKS bolts are awesome as well.

Michiguns Ltd. - AR-15 Tools and Accessories

 

[kcsmith]

Lightly chamfer the edge with a csink and call it a day.