In 1986, T/C electroless nickel plated (AA) some contender frames and barrels as a option. All metal surfaces internal and extenal were plated with AA the exception of sights and springs were plated. I belive?? the thickness was .002" or around that thickness.You have too remove the plating to use a AA barrel on a blue frame. They stop the plating because the plating color were not the same(off color). Hope that helps a little.
