There are at least two formulas available to hot blue stainless steel.   I use DuLite 3-0 salts.  The process is harder to use than regular salts, takes more tanks, temperature is more critical and is generally tougher all around.  The results are  the same as regular hot blueing.
Just like blueing carbon steel, stainless blueing is a stain, and does not add dimension to the metal.  There is some passification, whatever that is, so the results are not a tremendously high gloss, more like the factory finish on most guns.
  To find out if your  gun is stainless steel, put a magnet on it.  There should be some pull, but not as much as carbon steel.
  So, if you're tired of spooking game with your shiny stainless steel gun, or if you're in law enforcement and don't want to look like a perp, stainless steel blueing is for you. 

STAINLESS STEEL RIFLE BARRELS                                    $150.00
STAINLESS STEEL RIFLES COMPLETE                               $310.00
STAINLESS STEEL HANDGUNS                                                          $270.00            


Winchester 1894 receivers between 2,770,000 and 5,024,957 (1964-1981) were machined from a graphitic steel casting and will not accept normal blueing.  To make it more confusing, serial numbers 3,185,692 to 3,806,499 (1968-1972) were black chrome plated, and 3,806,500 to 5,024,957 (1972 -1981) were iron plated.
I can hot blue all of these, but must first grind off the plating.  The shiniest finish that can go on these is 400 grit ( about factory). 

RECEIVERS ONLY      $120.00
COMPLETE GUN         $295.00

George Roghaar Firearm Refinishing.
Winchester pre 64 model 70 with hot blued stainless steel barrel