Guns are made of 400 series stainless steels. It is much stronger that the 300 series of stainless, due to its higher carbon content. 416 is a usual firearms stainless. 304 and 316 stainlesses are used in industrial applications. The 440 series are more suseptable to rust and corrosion. A magnet will stick to all your stainless firearms, whether made by Smith or anyone else.