But you can have a stainless colored finish applied. Ruger has used a grey finish on the field guns for awhile. Most of the modern finishes include a stainless color. Robar has a slick silver finish it uses. Stainless guns are made of stainless steel and not "finished". I think you can have a "hard chrome" finish applied that was popular on 1911's a few years back, not a shiney finish.
Robar NP3 Firearms Finish Metaloy, Industries - Professional Gun Finishing - hard chrome, blue and polymer finish