450 - get a can of Wipe Out and getting a big or a whole lot of copper out of the barrel happens with just an overnight soak. (barrel angled slightly down, onto a towl for the overnight soak)

I use a mix of 50:50 Kroil Oil and Butches Bore Shine as a quick cleaning solution as well as after the Wipe Out overnight clean.

After using the JB, your 'smoother' bore shouldn't pick up much more copper - we can hope.