Copper or Rust on borescope?

[Maverick124]

Hey everyone...recently working on a 6mm Creedmoor and ran a Teslong borescope down the bore. In the first 1-2 inches of the rifling I'm seeing what is either copper or rust...but I'm not savvy enough with the scope to tell the difference. Looking for input, images attached. Thank you!

 

[B y r o n]

Try using the mirror attachment for a 90 degree view of the lands and grooves, you'll get a better view.

 

[vh20]

Copper. It is shiny. Also, it's mostly on the lands but not the grooves.

 

[Maverick124]

Thanks for the replies. I'll attach a better picture with the mirror for anyone's future reference.

 

[pmclaine]

It’s the “gay”.

All 6mm come with it.

Wear gloves when cleaning it or you may catch it.

 

[Baron23]

copper