Rust or copper fouling?

[u/gussy1412]

Hey folks, anyone able to help me with determining whether or not this is copper fouling or rust? The first time I shot this gun it rained on me, and it’s possible I didn’t get all the moisture off of it. I just cleaned the bore and ran an oiled patch through.

[u/swhissell]

Agree with others that this is copper. No worries!