Interesting thread. Color case by the traditional bone meal + other chemicals method involves heating to high temps and then quenching. Too much alchemy for me especially on modern heat treated chrome moly steel as in M-21 receivers. Cyanide "color case" might be better in this case but all it does is color the surface, no real effect on the strength of the metal. Like other posters I would ask, why do it? John Olin did the M21 in blued steel; why gild the lily? Silvers

I AM SILVERS, NOT SLIVER = two different members. I'm in the northeast, the other member is in MT.