I have an old Handi in 30-30 that I bought just to get the scope. I shot it and liked it so I started to reclaim it--re-finish the stock etc. When I bought it I gave it a thorough cleaning, took it to the range and was really surprised. I always give the barrels a real good cleaning after firing - but back to the subject. I sprayed some Gunk penetrating oil down the barrel, waited and ran a patch through--it came out green/blue could this be copper. Has any used this stuff before? Any ideas? Thanks