There are several reasons bluing will not take on a gun. One is it stainless steel. Nope. Two is the bluing solution correct. If so, is the temperature correct, Brownells has bluing info for their solutions., follow these almost perfect. Also to be blued, it must be alloy steel. not pot metal, not cast, just steel. Don't get any brass, copper, zinc or lead in the bluing solution.

lcjones

Yes. Various bluing agents and treatments exist.

It is a form of controlled rust.

In hot bluing, the steel parts are placed in a hot chemical bath that changes the outer layer of steel to black iron oxide. This helps protect the steel beneath it from further rusting. In rust bluing, the steel is exposed to moist air, and allowed to rust under controlled conditions.

Birchwood Casey makes a chemical that removes bluing. In addition, Naval Jelly, a popular rust remover, will also remove gun bluing. (Bluing is a form of rust) Be certain that you are dealing with blued steel, and not anodized aluminum. A magnet will not stick to aluminum, but both the Birchwood Casey product and Naval Jelly will corrode aluminum alloy very quickly.

I cant really answer this one any better than the wikipedia entry for gun bluing does.

http://en.wikipedia.org/wiki/Bluing_(steel)