Not armor piercing, its a common gimmick. It's a mild steel core which has the same properties as hard cast lead or heavy jacketed lead bullets. It will spark like a mother ****er though so don't shoot into dry grass/brush because if it strikes a rock you could start a fire. California went through some problems with this. Its the result of simple economics, steel is cheaper than lead and therefore a lot cheaper to produce.
Could I get one round, or, even just one bullet, for medical demonstration purposes ?
We at LSU Med have been trying to put our hands on one iron-containing projectile to use for an MRI demonstration. They have proven very, very elusive, so far.