"Bob Swinney" wrote in message
news:AUcQb.130087$I06.1122362@attbi_s01...
Kinda makes you wonder why stainless steel firearms are usu. left bright,
doesn't it?

Remington used to plate its stainless shotgun barrels with iron, and then
blue the iron (early '60s). There is black chrome plating used on stainless,
and blackened nickel. Maybe there is more. The last time I looked was 20
years ago.

There is some other treatment for stainless that can produce colors, but I
don't recall what it is. In any case, that was for some obscure industrial,
or aerospace application.

Ed Huntress