I've only used Blue Wonder Gun Blue on my Mini-ranch, to remove the brass marks that appear on the slide handle. (a little BW-Gun cleaner and some "0000" steel wool, the appaly blue wonder, and the brass marks are gone.
But I've used it to touch up the wear marks (front and back straps, hammer and trigger) on my BHP, and I've used it completely refinish my Marlin .444 which came out very nice. (sorry no pics avalible - no digital camera)
I used 6 coats on all the steel, which is now a very, very blued/black).
(If you do use it, make sure you use rubber gloves, the gun blue will stain your skin)
The other thing that I use, from Blue Wonder, on a regular basis; is their Gun Cleaner for cleaning the bore. That stuff it the bomb!