All I can say is WOW!!! http://www.youtube.com/watch?v=DAx0EWhWcEg Older video but its new to me. A-Square, Inc., in .557 T-Rex (Tyrannosaurus Rex). The rifle fires a .557-inch diameter, 750-grain bullet at 2,450 feet per second from a 13.8-pound rifle. Muzzle energy is a whopping 11,000 foot-pounds.