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A Tale of Two Crush Washers, or Two Crush Washers One Barrel, and other AR oddities
- Thread starter cmshoot
- Start date
In the case of that first set of pics, where the dude cracked his upper receiver lugs when attempting to remove the muzzle device, that dumbass 100% used the wrong tools/devices for the task.
It's a possibility that the muzzle device also wasn't installed properly, but the part he broke should not be part of the task he performed. He should have used a reaction rod from Geissele, Midwest Industries, etc.
There is also a possibility that the muzzle device was installed at the factory with some sort of thread locker, like Rocksett. In that case, there are specific steps that have to be followed when removing.
He should have stopped long before he got to the point that he did.
In the last set of pics, with the end of the barrel snapped off, I can't really comment as I don't know what happened there. I can come up with situations where SIG is at fault, and I can come up with some where the shooter was at fault. Also, no idea if the muzzle device was factory installed, or installed by the end user.
I gotcha. I know you are privvy to info the rest of us aren't, so I wasn't sure if you had been hearing anything. I think I had basically the same ideas based on what you said...but your thought process is clearer than mine lol
Was this a crack on me?
Greg relax bro…no one’s talking **** on you. He’s asking about quality of other gun manufacturers like sig or Seekins and if it was a quality issue or the original installer was just that bad.
No. I was saying that I have not heard any issues with SIG AR's that were from someone that I know personally, that witnessed the issue personally, and that I know well enough to know that they know their stuff.
I didn't see anything about that. Sorry.
It's better to check your specs as you're building, rather than waiting until your build is done and won't function properly.
Customer's new build. Ballistic Advantage 18" 5.56 barrel with rifle length gas system. It would eject the expended casing, but the bolt wasn't coming back quite far enough to pick up a new round from the magazine.
Gas block was reasonably aligned, but the barrel wasn't dimpled for the gas block screws.........so I dimpled it.
The spec for the gas port for this barrel should be .0995". I gauged the port and found it to be .087". There's the issue.
I reamed the gas port out to the proper size while the customer wait, and reassembled all. That should have taken care of the issue.
Customer's new build. Ballistic Advantage 18" 5.56 barrel with rifle length gas system. It would eject the expended casing, but the bolt wasn't coming back quite far enough to pick up a new round from the magazine.
Gas block was reasonably aligned, but the barrel wasn't dimpled for the gas block screws.........so I dimpled it.
The spec for the gas port for this barrel should be .0995". I gauged the port and found it to be .087". There's the issue.
I reamed the gas port out to the proper size while the customer wait, and reassembled all. That should have taken care of the issue.
If you're installing a gas block that uses set screws, the barrel needs to be dimpled. It may run for a while, but eventually the gas block is going to start walking forward. It moves far enough forward, or rotates to one side, and the gas port in the gas block will no longer be aligned with the gas port in the barrel.
Customer brought in an AR that he had bought from another metro area shop. It had stopped cycling when fired, so he took it back to the shop where he bought it. An employee there found that the gas block had moved forward. He "fixed" it by putting it back in place, reusing the old gas block screws, and tightening it back down. The barrel was not dimpled.
Next range session, the gas block walked forward again. Customer brought it in to me at TruPrep.
I pulled the gas block, threw away the old set screws, and cleaned the red Loctite out of the holes in the gas block. I dimpled the barrel twice, and installed new set screws with Rocksett.
I also found that the gas key was not securely installed. Overall, except for the gas key, the BCG looked decent. It was marked "1B1B6" on the left side of the carrier (in the area where Colt commonly stamps their "C"), and I hadn't seen that before. It was phosphate coated, and the carrier bore was hard chromed. The bore in the gas key, however, was not hard chromed.
Removed the old gas key and cleaned up the mounting surface on the carrier. Decked the new gas key, and installed to the carrier. I used Permatex on the mounting surfaces, and in the two threaded holes. Screws were Optimized Carrier Key Screws (OCKS) from Michiguns, who also made the staking jig I used to stake the screws after torquing to 58 inch/pounds.
Lubed everything and reassembled.
Customer brought in an AR that he had bought from another metro area shop. It had stopped cycling when fired, so he took it back to the shop where he bought it. An employee there found that the gas block had moved forward. He "fixed" it by putting it back in place, reusing the old gas block screws, and tightening it back down. The barrel was not dimpled.
Next range session, the gas block walked forward again. Customer brought it in to me at TruPrep.
I pulled the gas block, threw away the old set screws, and cleaned the red Loctite out of the holes in the gas block. I dimpled the barrel twice, and installed new set screws with Rocksett.
I also found that the gas key was not securely installed. Overall, except for the gas key, the BCG looked decent. It was marked "1B1B6" on the left side of the carrier (in the area where Colt commonly stamps their "C"), and I hadn't seen that before. It was phosphate coated, and the carrier bore was hard chromed. The bore in the gas key, however, was not hard chromed.
Removed the old gas key and cleaned up the mounting surface on the carrier. Decked the new gas key, and installed to the carrier. I used Permatex on the mounting surfaces, and in the two threaded holes. Screws were Optimized Carrier Key Screws (OCKS) from Michiguns, who also made the staking jig I used to stake the screws after torquing to 58 inch/pounds.
Lubed everything and reassembled.
