Howdy
Smith and Wesson has been nickel plating guns since 1857. They actually finished more of their small Top Breaks with nickel plating than they did with blue. The little Number One, 5th Type at the top of this photo shipped in 1859. The silver plating has almost all worn off the brass frame. The other two, the Number One 2nd and 3rd Issues, are both nickel plated.
38 Single Action (Baby Russian) that shipped in 1876
32 Single Action that shipped in 1889.
38 Military and Police, Model of 1899 that shipped in 1899.
32 Safety Hammerless that shipped in 1905.
38 Double Action Perfected that shipped in 1917.
Triple Lock that shipped in 1915.
My favorite nickel plated Smith, a New Model Number Three that shipped in 1882 and was refinished at the factory in 1965.
I have a few other nickel plated Smiths lurking somewhere, but those are most of them.
But I got off track. Nickel does not adhere well to steel. Copper does. So before a steel revolver is plated with nickel it is first plated with copper. Then the nickel plating will form a good bond to the copper. The problem with Hoppe's #9 is the ammonia in it can attack the copper underneath the nickel. Particularly if there are any chips or scratches in the nickel, allowing the ammonia access to the copper. Here is the caution on the back of a bottle of Hoppe's #9. Notice it does not say not to use it on nickel plated firearms, it says not to soak them in it and to wipe the nickel dry after cleaning.
