I blued a lot of guns in my smithing career, but when I retired I sold all that stuff. A couple years ago, I built a competition muzzle loading pistol and wanted to blue it. Didn't want to buy 50 pounds of bluing salts and a whole set up, and having worked as a chemist for awhile, I started looking to make some hot blue salts. A net search showed someone already had, and I modified their process a bit, but it worked as well as the expensive salts from Brownells. Getting a gun blued these days is expensive, long waits, shipping costs etc. and the people often use soft buffing wheels that round off edges, dish flats, distort lettering etc etc. and glass beads that are too coarse for my taste. A careful hobby gunsmith can prep their own pistol as well as, and probably better than some commercial outfits I've seen, with patience. The ingredients are found at hardware stores or garden centers and pretty cheap. Anyway, anyone wanting to try it, let me know & I'll email a copy of the process. Not enough room in a post here. Or they can put it in articles, if anyone knows how to do that??