People say they are the same... But I can find no data on the 223 tumbling and fragmenting. They do move at the same rate of speed... The Hyperstactic shock alone has been proven to kill animals when the bullet hits the soft watery body and forces all that blood into the skull. If the animal does not die it suffers massive brain damage and is impaired. [ame=http://www.youtube.com/watch?v=EZjKI7jt2gQ]223 stopping power demonstration - YouTube[/ame] this is the best vid I have seen on 223 damage. It left a huge exit wound and I am happy with my choice in 223.