Ever seen a spot like this in a barrel?

[WEATHERBY460]

New Savage 6MM Creed. I cleaned before shooting and cleaned after I shot 2 rounds thru it to see if it went away. I sort of don't think it's copper. What are your thoughts?

 

[ShtrRdy]

Looks like a stain. Run a couple dry patches through and see if it's still there.

 

[WEATHERBY460]

Yes it's still there. Looks like it's on top of the filling in the first picture.

 

[Gabe22BR]

Clean that copper spot out, should be clean then…