Pumper is right all it is is a chemical controled oxidation. But the key there is chemical. The use of different chemicals and temps give you different colors and durablity. Ya know how some blued guns look more grey blue or some look black. The metal under the blue also plays apart in how the blue will look. A rough machined metal will give you a matte finish like found on most hunting guns. I highly polished metal will give you that deep dark gloss blue like on the wingmaster or preimer. To this day the absolute best blueing both in looks and durability I have ever seen on a production gun IMO is the Colt Royal Blue. Found most commonly on their Python handguns. You see one that is polished and cleaned WOW it will take your breath away.
A forum community dedicated to Shotgun owners and enthusiasts including the Remington, Beretta, and Mossberg shotguns brands. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!