If anyone is interested in reading the manual Brownells sends with their "NitreBlue" bluing salts, here is the link.

http://www.brownells.com/aspx/NS/General/DisplayPDF.aspx?f=Inst-362NitreBluingBluing.pdf

Barry, not to pry, but there seems to be a lot of confusion between charcoal bluing and carbonia(carbona?) bluing. I once read somewhere that Carbonia bluing was trademarked by the American Gas Furnace Company and that the special Carbonia oil was only available thru them, yet they only licensed it to Smith and Wesson? I have no idea where I read that, but is there an actual difference between the two and if so what is it? Thanks