From back in 2003 when GunBlast described the 'Target Gray' finish on an SP-101
http://www.gunblast.com/Ruger_SP101.htm
quote> Since the introduction of the SP101, it has been offered in several variations and chamberings, the latest of which is the new .357 Magnum Target Gray revolver tested here. The Target Gray is a special process that Ruger uses on a few of their stainless revolvers to produce a unique finish. The Target Gray retains all of the positive properties of stainless steel, such as durability and corrosion resistance, while providing a darker non-glare finish to the surface of the metal. Ruger has offered this finish in the past on some of their target rifles, hence the name. Ruger is now offering this new finish on a few of their double action revolvers in limited numbers. On these revolvers, perhaps it should be called a "Tactical Gray" finish, to best describe its useful application. Whatever it is called, it is a very good-looking finish that is much more durable that the bluing on a carbon steel gun, and is not shiny and reflective like a standard stainless finish. The result of applying the Target Gray process to the SP101 is a handsome, businesslike appearance that won’t shine like a mirror when drawn from its holster. <end
...Jimbo