What is the difference? They are all steel core penetrators as far as I know, but what is the real difference between the different colored tip? I have some .308 silver and black tips and some .50 silver tips and I also have a bunch of .224 FMJ, all of which attract a magnet that are all pulled and re-sized military projectiles. So what exactly do the different color tips mean? I have also seen blue tips which I am told are tracer rounds (why aren't they NATO less-than-lethal rounds? NATO shoots blue bubblegum ball ammo, don't they?) Anyhow, just trying to figure this stuff out.