This 'Mark 8' 2,700 pound armor piercing (AP) projectile is fired from one of the nine 16-inch, 45 caliber Mark 45 "Big Guns" aboard Battleship USS Alabama (BB 60). It travels at a speed of 2,300 feet per second or 1,568 miles per hour; more than twice the speed of sound. The guns are accurate up to 20.97 miles away from the battleship. Visit USS Alabama Battleship Memorial Park 1-10 exit 30, Mobile.