They are possibly using "plated jackets" have a magnet to them see when they appeal to a magnet. You then have steel plated copper coated bullets. Yet another uncomplicated exam. Have a pocket knife to your jacket if they are plated it is going to Lower into it a lot https://buyredarmystandardammunit50503.ampblogs.com/getting-my-fn-5-7-28-mm-40gr-ammo-to-work-71405721