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