Pro Shot Products KleenBore Black Magic Bluing Solution - 2oz - Black Magic by KleenBore is a premier, high performance cold bluing solution, previously available only to gunsmiths, produces a deep, penetrating action to restore worn or scratched gun metal to like-new finish. It’s the choice of many major firearms manufacturers for touching up guns before they leave the factory. Packaged in a container with a child-resistant cap and expert, easy-to- follow instructions.