cm: regarding original factory heat treating processes as compared to re case hardening, when a factory heat treated a receiver the metal started out soft and to a known spec as rolled or cast or perhaps annealed to a known spec.
as previously indicated, a low heat, chemical process recolors the receiver only and does not change the original factory heat treatment of the receiver... some like the appearance of chemical induced case colors. some do not...perhaps it is best to just leave a fine old gun alone and let it be as is? but, if you must recolor, it makes more sense to me to not mess with the functional parts of the gun, particularly the receiver. better to keep it as originally manufactured and avoid the unintended consequences of reheat treating receiver metal.
