Bad gas rings on new bcg?

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[ARCHIVED THREAD] - Bad gas rings on new bcg?

Posted: 11/5/2022 5:03:44 PM EDT

Brand new BCG, nitride from PSA.

Probably about 140 rounds of tula steel and 120 of pmc xtac on it.

Was cleaning it and the bolt felt loose in the carrier. Like a well broken in bolt, not close to new.

Reassembled it and put it bolt face down and the carrier went down easily and multiple times.

Works fine. Forget about it or fix something?

Posted: 11/5/2022 5:06:35 PM EDT

[#1]

Sounds like bad gas rings on the bolt OP.

Posted: 11/5/2022 6:53:33 PM EDT

[#2]

So, pop it apart and inspect the gas rings.

Posted: 11/5/2022 8:57:55 PM EDT

[#3]

Test is bolt up/pulled up with B/C carrier side down on table, and rings should hold the bolt up under just the bolt weight.

But yes, would pull the bolt to check the rings, and make sure that the rings are all installed with the sharp sides towards the bolt face.

In this photo, all the rings are sitting rounded side up (the top edge as the rings are stamp cut), so when they are being mounted on the bolt, the bottom sides should all be facing the front of the bolt face.

And why the factory sharp edge of rings towards the bolt face, helps to cut the carbon from the side walls for the gas chamber forward when the bolt goes under 35Kpsi during unlock, and allows the bolt to lock back up with less force during loading. Plus with rounded side edges towards the tail of the bolt, make putting the bolt back in the carrier a hell of lot easier, and you don't end up killing a gas ring by sharp edge against sharp edge to that can cause ring binding against themselves.

Posted: 11/5/2022 9:13:57 PM EDT

[#4]

Quote History

Quoted:

And why the factory sharp edge of rings towards the bolt face, helps to cut the carbon from the side walls for the gas chamber forward when the bolt goes under 35Kpsi during unlock, and allows the bolt to lock back up with less force during loading. Plus with rounded side edges towards the tail of the bolt, make putting the bolt back in the carrier a hell of lot easier, and you don't end up killing a gas ring by sharp edge against sharp edge to that can cause ring binding against themselves.

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35K? its really that high "inside" the bolt?

and...............are you really certain you have the sharp edges oriented the correct direction?

Posted: 11/5/2022 10:30:45 PM EDT

[#5]

Quote History

Quoted:
Test is bolt up/pulled up with B/C carrier side down on table, and rings should hold the bolt up under just the bolt weight.

But yes, would pull the bolt to check the rings, and make sure that the rings are all installed with the sharp sides towards the bolt face.

In this photo, all the rings are sitting rounded side up (the top edge as the rings are stamp cut), so when they are being mounted on the bolt, the bottom sides should all be facing the front of the bolt face.
https://www.rooftopdefense.com/wp-content/uploads/2020/09/gas-rings.jpg

And why the factory sharp edge of rings towards the bolt face, helps to cut the carbon from the side walls for the gas chamber forward when the bolt goes under 35Kpsi during unlock, and allows the bolt to lock back up with less force during loading. Plus with rounded side edges towards the tail of the bolt, make putting the bolt back in the carrier a hell of lot easier, and you don't end up killing a gas ring by sharp edge against sharp edge to that can cause ring binding against themselves.

View Quote

Damn dude.
Never knew that.
Thanks!

Posted: 11/5/2022 10:41:57 PM EDT

[#6]

Probably a carrier cut for chrome and when nitrided it leaves the gas ring bore oversized.

Posted: 11/6/2022 12:59:08 PM EDT

[#7]

Bolt assembly must not drop
out. If weight of bolt assembly allows it to drop out of key and bolt carrier assembly, replace the bolt rings

Bolt assembly must not drop
out. If weight of bolt assembly allows it to drop out of key and bolt carrier assembly, replace the bolt rings

Attached File

Posted: 11/17/2022 10:44:43 PM EDT

[#8]

Quote History

Quoted:
Test is bolt up/pulled up with B/C carrier side down on table, and rings should hold the bolt up under just the bolt weight.

But yes, would pull the bolt to check the rings, and make sure that the rings are all installed with the sharp sides towards the bolt face.

In this photo, all the rings are sitting rounded side up (the top edge as the rings are stamp cut), so when they are being mounted on the bolt, the bottom sides should all be facing the front of the bolt face.
https://www.rooftopdefense.com/wp-content/uploads/2020/09/gas-rings.jpg

And why the factory sharp edge of rings towards the bolt face, helps to cut the carbon from the side walls for the gas chamber forward when the bolt goes under 35Kpsi during unlock, and allows the bolt to lock back up with less force during loading. Plus with rounded side edges towards the tail of the bolt, make putting the bolt back in the carrier a hell of lot easier, and you don't end up killing a gas ring by sharp edge against sharp edge to that can cause ring binding against themselves.

View Quote

Round towards the Rear

Posted: 11/29/2022 3:03:45 PM EDT

[#9]

Quote History

Quoted:
Test is bolt up/pulled up with B/C carrier side down on table, and rings should hold the bolt up under just the bolt weight.

But yes, would pull the bolt to check the rings, and make sure that the rings are all installed with the sharp sides towards the bolt face.

In this photo, all the rings are sitting rounded side up (the top edge as the rings are stamp cut), so when they are being mounted on the bolt, the bottom sides should all be facing the front of the bolt face.
https://www.rooftopdefense.com/wp-content/uploads/2020/09/gas-rings.jpg

And why the factory sharp edge of rings towards the bolt face, helps to cut the carbon from the side walls for the gas chamber forward when the bolt goes under 35Kpsi during unlock, and allows the bolt to lock back up with less force during loading. Plus with rounded side edges towards the tail of the bolt, make putting the bolt back in the carrier a hell of lot easier, and you don't end up killing a gas ring by sharp edge against sharp edge to that can cause ring binding against themselves.

View Quote

Learn something new everyday. Damn you! Now I have to check every one of them.......