Check it with a magnet. I owned SEVERAL Model 59s, all in stainless 659. Defended myself with one against a couple of pit bulls, and one chow at very close range. Hit where I aimed it multiple times in all three cases. Sold it the next day, after the third encounter. All of mine over the years were very reliable, although the transition from double action to single action, and back to safe, MUST BE PRACTICED, until it becomes second nature, or it is a very dangerous condition under stress.