I field stripped my AR yesterday, but to my surprise, found some discoloration on the bolt lugs and webbing, towards the front end of the bolt. Here's a picture I took:



It looks a little brown near the front, as it seems to me. I hope to heaven that's not rust. I scrubbed it with CLP but the discoloration has not gone away.

Of course I started to panic when I saw this. It hasn't been wet, and I've kept it clean since the last range session. This is a brand new bolt that's only been to the range once. I've never seen an AR bolt rust before, either on a service M4/M16 or a privately owned AR of any kind. Am I going crazy, seeing things that aren't there, or is this something to be concerned about?

If anyone's wondering, it's an AR15 Performance Recon 6.8mm upper & BCG attached to a lower I assembled myself on a Stag stripped receiver.