I have heard that it is ok to use Hoppes because S&W did not first plate with copper then nickel on top I also have heard that you shouldnt anyways. I have 1 nickel gun and have chosen not to use Hoppes #9 on it....just in case
A fellow forum member sent this to me and it really works. I now do this on all my nickel guns.
CLEANING AND POLISHING A NICKEL GUN
The first step is to thoroughly clean the gun. I use a product called Prolix. It is safe to use on all nickel guns and cleans them very well. Clean the cylinder, barrel, the entire gun.
Once the gun is cleaned, you will need to decide if you want to polish it or not. Many times with nickel finishes, the finish has oxidized in places making the finish appear to be milky or cloudy. Polishing can bring those areas back to a nearly new luster. However, depending on the severity of the milky or cloudy areas, it will take some time. DO NOT use a buffing wheel on a nickel finish.
If you decide to polish out the finish, I use Flitz. It is a polish that is not very abrasive, but abrasive enough to remove the milky or cloudy areas. Using a soft cloth, cotton T shirt works for me, put some Flitz on the cloth and began to rub it on the finish. The area of the cloth will immediately began to turn black. Turn the cloth, as it blackens, to a clean area of the cloth and continue to rub the area where the Flitz has been applied. Rub until the cloth no longer become black. Try a small area first, just to get the feel of what you will be doing. Taking another cloth, still a soft cotton cloth, and buff the area you have completed. You should see a major difference in that area and the areas around it. Continue doing the entire gun using only your fingers and moderate pressure while rubbing and buffing. As I stated earlier, this can be very time consuming, but the end product will be worth the effort. If the face of the cylinder is blackened from carbon, use Flitz on it as well. Following the same instructions.
Once you have completely polished the finish of the entire gun, you are ready to wax and protect the finish. I use a product called Renaissance Wax. The initial cost will have you shaking your head, but I have had a 7 oz can for over two years. It does not take very much at all, and the lighter the coat the easier it is to buff out. Do one section of the gun at a time. Do not let the Renaissance Wax dry before buffing out. You will like the ease of application and buffing. It is just a great product. You will find that the wax protects the finish, and will make it easier to clean the next time. Speaking of the next time, use Prolix to clean the surface, then just apply the wax. (One word of caution here, I use Flitz on my nickel finishes about twice a year. Flitz, though not a real abrasive product, is still a polish and is abrasive. Do not overuse Flitz.)
This is what I do, and it works on my nickel Smiths and Colts.