It is dependent upon how acidic that person's sweat is (or isn't). Everyone is different. My fingerprints don't seem to do much damage if left on the metal for a day or two but I used to shoot competition with a guy whose sweat would cause stainless steel to rust in an hour or less. If he touched a blued gun you better have an oily rag real handy. I did not believe it until I saw it happen. It was amazing. My advice is to wipe the gun down with a slightly oily rag as soon as you notice any prints on it. Polarized oils are available which will neutralize the acid and prevent corrosion. I used to work for a gunshop that set up at a LOT of gunshows in the midwest. One of my jobs was to keep a close eye on 3 or 4 tables filled with handguns that were being handled constantly by the public and make sure they stayed oiled. We never had any of them rust but it was a full time job. I kept a small brush loaded with oil and just constantly picked up guns some one had just set down and re oiled them. Then at the end of the show they all had to be reoiled and put back in their boxes. A brush works much better than a rag. Our oil of choice was Birchwood Casey's Sheath. I do not know if it is still being produced. It is a polarizing oil and works very well. All I use now is Breakfree CLP or Collector and it does a very good job on all of my blued steel guns. I have shot matches several times in pouring rain and then drove home an hour away and pulled the blued guns out of my bag and headed for the air compressor to blow all of the water out of it. With nothing but CLP on the metal they did not rust after that abuse. Just stay on top of it and keep them oiled.
Last edited by drail; November 19, 2012 at 11:33 AM.