Cam pin wear or cracking?

[aaronb]

I've been doing inspections on our rifles and am wondering about a mark on all of the cam pins. I initially thought one of the cam pins was cracking because I could feel a "ridge" or raised area on the pin with my fingernail. I looked at all of them so far and they all have it. We have spare pins that are brand new and they do not have any of the marks on them.

The marks on the pins match up perfectly with the bolt carrier so I am wondering if the pins get slightly battered or peened by the bolt carrier during firing leading to being able to feel a slight ridge?

Thanks for any information.

[Buck]

The answers you seek are located ====> HERE (https://www.m4carbine.net/showthread.php?t=3807) ...

B

[aaronb]

Buck,

Thanks for the link. I read that thread awhile ago but it didn't click at the time. I was looking more at the info on bolts and didn't see the info about the cam pins. Although the info on the cam pins is limited I think it did answer my question. The bolt carrier beats on the cam pin (harder in the carbine length gas system) and I assume that is what is leaving the small ridge that feels like a crack on the pin. The "ridge" follows the same curved line as the hole in the bolt carrier which leads me to believe the ridge is formed by being hammered on by the carrier and not a crack.