Anyone know anything about armor piercing rounds? I don't, but I could imagine them causing sparks where a normal FMJ would not.

Edit: Did some youtube research. Heres what I found:

.308 vs. stage 3 body armor plate

.308 AP incendiary rounds

standard .223 AP rounds do not seem to produce the same effect

.223 AP incendiary rounds vs. stage 3 body armor plate

I can only conclude that its possible this was special effects, but its just as possible the shooter had incendiary ammo. If its was incendiary, it wouldn't shock me if we see a huge push to outlaw AP ammo. This guy does a pretty good rundown on the past attempts to ban armor piercing rounds.