Got a photo of the back of the carrier? Could there be a burr, or blem that is causing the mark? Is it just a surface mark, or is there depth to it? That carrier should ride on the buffer tube the entire cycle.

Carrier was unremarkable, smooth, unblemished... pristine.
There is depth to the ring.

I'm starting to wonder if the spring isn't up to the weight of the auto carrier.... Or if the Black Hills reman .223 is loaded hot.

Certainly a puzzler.

Will start with replacing the buffer and spring. Will use factory new .223 to start out with the new parts. But all will have to wait for budget reasons.

Is the spring possibly being coil bound?

Spring had no indications of that. All seemed fine.

My bet is it’s soft metal.

This blicky has a switch and spits more than 500.
Dirty vs Wipe Off




BLACK HAMMER ARMS
07/02 NFA Dealer

http://www.blackhammerarms.com
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There have been carriers lately have some burrs on the end that causes that wear. Haven't heard of any from Colt, but I know the OEM's for the industry have had some.

Inspect the end of your carrier.

A2 upper with acog mounted on the carry handle makes me so honny!!

Hmmm…

Yeah, I saw that too Sinus, That's some funky shit. Like dreadi said, soft metal in that buffer. Replace the buffer and move on.

That's the Black Hammer Arms full auto fucky, but my buffer has nicks on the edge, too. Looks like where it contacts the retainer pin. Didn't think it such abig deal like the divot in the face.

It's soft, get a new one and move on. Those marks on the buffer edge didn't come from the Detent Pin though, there was another source for that.

Seems too obvious, but double check that you have a rifle spring and not a carbine spring.

Other than that, I suspect your buffer was poorly anodized. These should all have "hard anodizing" which is different and much harder and more wear resistant than ordinary anodizing, but maybe your buffer wasn't hard anodized or the process used failed to give the desired surface hardness. Same as with AR receivers - all the wear resistance comes from the anodizing; if that's too soft or once it's worn through, wear will happen very quickly and the most realistic fix is to replace the part.

As to why it's happening, besides inadequate anodizing - your buffer is most likely rotating against the carrier as the spring compresses, that's what coil springs do and there's nothing to prevent it from happening. So with every shot, and little or no wear resistance in the buffer, you've got some rotational movement and the carrier rubs a groove in the buffer. And who knows, maybe it started with some sand or grit on the buffer face, or the gun was fired dry a bunch? Regardless, for that to happen in 500 rounds indicates something was badly wrong with the contact between those two parts, and I'm betting on poor anodizing as the most likely and obvious culprit.

The simple fix is to just buy a new buffer, and might as well buy a new spring with it too. I'd also make double sure the contacting surface of the carrier is nice and smooth so it doesn't happen again.

Yep. I agree with much of that.

Spring and buffer came with the rifle so should be correct.
I'm pretty meticulous with running clean gear and don't have to get in the dirt for a living with my guns, but still, I guess some hard contaminant could have been introduced at some point.

I'll recheck the carrier that's in it. I've also got a call in to the guy to whom I donated the original carrier for his build. I'll get pics of the original carrier and his buffer face if I can.

Might be time to try a JP spring or something too.

As long as you don't use that JP silent capture spring. They sound like a squeaky box frame in an old hotel.

Things happen.


BLACK HAMMER ARMS
07/02 NFA Dealer

http://www.blackhammerarms.com
http://www.facebook.com/blackhammerarms
https://www.instagram.com/blackhammerarms