It all has to do with the composition of the "stainless" steel. I was an instrument specialist for a surgery in a major hospital for a little over ten years. If it isn't some sort of polymer, its stainless. Owing to the corrosive nature of bodily fluids and such they had to be. Anyway, the only truly stainless instruments were made of austenitic, high nickel content SS and those instruments weren't under a lot of stress, they were absolutely nonmagnetic. Ones that were had to be manufactured with a much higher carbon content. While they were durable, they were subject to pitting from corrosion if not properly cared for, if they got pitted, they were thrown out. SS in a firearm will only slow the corrosion process to a small fraction compared to a blued steel one, but they will still degrade if not taken care of. So, the moral of this long-winded tome is: make sure the surgeon doesn't leave a SS pistol in your gut before closing you up.