The reports talked about a .223. I don't know if that's a spent .224 bullet or a .223 cartridge case they found. We still don't know if it's from a rifle or handgun.
The various .223 caliber cartriges are accurate to 400 yd from a contender.I heard an interview with some LEO (sheriff?) this AM. He said they made the determination from the bullet, no cases had been found, and mentioned .223 and .222, they former being the more likely based on usage.