Originally Posted by petenz
The interior surface of the barrel is horrible though, there are tool marks visible to the naked eye.
To help the interior of your barrel use "Microlon Gun Juice "
It cleans and treats your firearms. Microlon Gun Juice. It is a super lube that gets pushed into the pores of the steel to provide a barrier between your barrel and the bullet, resulting in less copper fouling and increased velocities, and longer barrel life amongst other things.