It's amazing. Sometimes I sell knives to people who know so much more about the subject than me they blow my doors off. A gentleman from Omaha, Neb., who recently bought several knives told me about Renaissance Micro-Chrystalline Wax Polish. It is used in museums to protect valuable furniture, leather, paintings, metals, marble, ivory and other surfaces. It comes in a little can only 2-inches high and holds 2.25 ounces. It prevents fingers prints, shines, preserves and polishes. It cost about $17. I don't know if it is good for gun metal or not. I suppose it depends on the type of metal. I highly recommend the product, however, for your knives, swords and other edged weapons.