Weird Ar wear pattern

[Savage Jav]

Hey all. I just got back from the range and noticed a different wear pattern starting in my Ar. Never seen anything like this before. It's just behind the locking lug recess. My only guess would that it's from a cmmg .22 kit that I just picked up but I even sought that. It dig into the receiver pretty good but I still think it's safe to shoot. Not sure what could of rubbed in that area. Here's some pics and any thoughts would be appreciated.

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[Joe13]

What's the BCG look like?

 

[v0lcom13sn0w]

are you shooting just 22lr with a conversion or are you shooting 5.56 through it too? judging by the pics, its hard to see but the shell deflector doesnt have a lot of wear so im assuming not a lot of rounds have been fired through the gun.

ive built over 30 ARs and on every one of them i take and lube up the bolt carrier group and cycle it about 100 times with the charging handle until it developes this grey slurry if oil/metal. i then cycle it another 100 times with that slurry of metallic oil to really lap the bearing surfaces and flashing left over by the manufacturing process.

dunno if thats what youve got goin on but i just felt like givin my .02

 

[308]

Personally I would clean everything off with contact cleaner, mark the assumed interference areas of the receiver and bolt carrier with a black sharpy, then cycle it a bunch, then check the wear areas.

 

[oli700]

that galling you are pointing at with the screwdriver , its from the cam pin digging its way out of its nesting spot upon unlocking of the system......its a sign that the system is unlocking too fast, the carrier is moving rearward faster than the bolt can unlock and as a result its tearing the cam pin over the corner before it has cleared on its own with a full unlocking of the lugs, or just a micro second to soon
The mark wont hurt anything , keep running it a lot of AR's have this .
However if your system is unlocking way too fast it will continue its wear but on the bolt lugs .