I asked that same question to the people at Krieger, and Pac-Nor.....not a whole lot according to them...other than rust RESISTANCE, some believe that stainless is easier to machine than chromemoly (i think it's that way, might be reversed) and iv'e read that it's not great to use a SS barrel in sub zero temps..????? but Sinman and Jim from northland, and Fred from SSS can probably say if i have my facts wrong....I hunted elk this past January with a SS 300 RUM at -8 degrees and had no problem.....can't blame the miss on it.....rsbhunter