[Coltsaa]

Anyone know the best way to remove the base copper plating under nickel used on most handguns? Up until now I have been having good luck soaking the parts in nickel remover which turned the parts a black color which when washed left the metal free of nickel and copper. I just ran into a Colt made in the 60's that the stripper dissolved the nickel but left the copper untouched. Mixed fresh solution and same results.
I am fairly new to this plating process(bright nickel finish) but have had excellent results thanks to Caswell! I have a power supply from Caswell if elecro-stripping is what I should be doing. Whats the best way? Any advice will be greatly appreciated!

I used the search function but didn't find what I needed.