Duddn, The nipple is just a soak-er. By that I mean warm water and a little dish soap. Let it soak for awhile. Now the nipple hole. If you need to clean the whole gun. If it is the type which you can remove the barrel. Do so and in to the tub. Hot water and soap and your normal cleaning brushes. If the nipple hole is caked up and rusted. I use an old 22 bore brush and powder blast. It takes a little while but it can done. After you get the hole and the nipple clean. Use pipe cleaners for the inside of nipple. And the nipple hole all the way in to the barrel. By that I mean the small hole from the nipple into the powder charge. Now you need to dry all parts, some people use a blow dryer, the oven for pistols. I have used both but I like the dry patch by the way you should use for barrel before drying with heat. Make sure the patch comes out clean. After everything is dry I use bore butter on nipple and interior of barrel. Good looking TC 54
The little rust if not to bad, oo steel wool and oil. There is nothing I know of that you can do one spot. And not be noticed with out doing the whole barrel.
Just do the best you can and keep it well oiled.
MUZZLESMOKE If you shoot black powder shoot it out of Pedersoli.....
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