Hello, I will try to get straight to the point and ask what should I be looking for when checking my pistols for any signs of rust? Is there any signs that it could rust before it actually happens, and also where on a pistol is the first place rust usually shows up? Is it more likely to rust on the outer surface and finish of the gun, the barrel, or the internals such as the extractor or any of the springs or little parts inside the frame?