Bob, the best rust bluing solution that I've used is made by Mark Lee. I've used Herters, Laurel Mountain, made my own from all the different compounds in  a recipe from Howe's book and still go back to Mark Lee's. If you're looking for caustic bluing salts, you might try Dulite as they used to sell it in small pails.

You have boiled it I hope? It wont turn dark until it's boiled. 
I also have had good luck with Mark Lee Express Blue rust bluing solution. Takes far less time between applications, and turns very dark.

Steam cabinet will help, need to get the steel warm and moist. I use Algiers book to get a home mixed recipe to blue most things, can nitre blue as well but prefer the rust blue.
Gumpy

craigster wrote on Feb 6^th, 2023 at 10:09pm:


I'm a fanboy of Bob's solutions. In truth I've had success with Laurel and Pilkington's too, but I live at dead nuts sea level and have never experienced issues with attaining uniform rusting. I barely have to warm my damp box in the summertime.

Bob, 
there's a lot of opinions being said and they all work given the circumstances.   
I'll admit when it comes to the caustic blue, oxynate #7 the results are tough to beat if you want that type of finish and have the desire to mess with it.  I don't care for either now in the current gun builds. 
A few years back I switched to the rust blue method, nitric fuming and a damp cabinet, it's even more effort but it matched the originals in result.  I don't have the time to do this anymore and most recently I tried all the wipe on solutions, some work better for me than others.  Mark Lee's blue and brown solutions have given me the best results.   
There are two things that I have carried over from the original rust blue that have given me stellar result, the first is to always use distilled water - and watch your temp, right at boiling seems to always take my color to a definite black rather than blue, come down slightly from that.  The second thing, you are probably operating at the same altitude as me? nearing 5000'? I purge my water for a minute or so with pure oxygen, from my oxy-act torch setup.  This generally gives me a more even distribution in less cycles.
Something more to think about.
Greg

Thanks for all the input!  The points about elevation, local humidity, damp box (which the Pilkingtons included instructions do not mention) are all appreciated.  I was hoping for a workable solution to my not having enough caustic salts left to make a solution in my big tank.  I'm not trying to blue anything expensive and certainly not anything that is here for decoration.  Anything like that goes to the qualified gunsmith.  Just trying to get parts and a barrel all to roughly the same (hopefully) bluish color.  Maybe someone has a partial amount of caustic salts under the bench I could purchase.  For now I will procede with the purplish brown I'm achieving.  Maybe it will catch on.  As a side note, I would far rather put a pewter tip on a Sharps forend than see if I can get these colors correct.  Reference to forend discussion earlier this winter.  Thanks for allowing this ramble.
Bob