Find great deals on eBay for gun barrel blue. Shop with confidence. I got an H&R Pioneer bolt gun. It's my first project gun. First I got to replace the firing pin striker. How to Blue a Gun Barrel. Black oxidizing, or bluing, is a method of treating steel to create a thin protective shell around it. It works by turning red iron oxide. If you already have an account, sign in. Immerse the gun parts in boiling water. Stainless steel gun parts are immersed in a different chemical solution, this one made of a mixture of nitrates and chromates. You can do gun barrel blue lot of guns with this kit. Item can be shipped within U. Published 1 month ago by BSSJr 5.