

Each gun weighed about 239,000 pounds (108,000 kg) without the breech, or 267,900 pounds (121,500 kg) with the breech. About 43 feet (13 m) protruded from the gun house. The guns were 66 feet (20 m) long - 50 times their 16-inch (410 mm) bore, or 50 calibers, from breechface to muzzle. The primary armament of an Iowa-class battleship consisted of nine breech-loading 16 inch (406 mm)/50-caliber Mark 7 naval guns, which were housed in three 3- gun turrets: two forward and one aft in a configuration known as "2-A-1". There are concussion effects on the water surface, and the 16-inch (406 mm) gun barrels are in varying degrees of recoil. Main battery Turrets USS Iowa fires a full broadside of nine 16 inch (406 mm)/50-caliber and six 5-inch (127 mm)/38-caliber guns during a target exercise.

Each battleship also received four Harpoon missile magazines, Phalanx anti-aircraft/anti-missile systems, and electronic warfare suites. When reactivated and modernized in the 1980s, each battleship retained the original battery of nine 16-inch (406 mm) guns, but the secondary battery on each battleship was reduced from ten twin-gun mounts and twenty guns to six twin-gun mounts with 12 guns to allow for the installation of two platforms for the Tomahawk missiles. Each of the four battleships carried a wide array of 20 mm and 40 mm anti-aircraft guns for defense against enemy aircraft.

The secondary battery of 5-inch (127 mm) guns could hit targets nearly 9 statute miles (14 km) away with solid projectiles or proximity fuzed shells, and was effective in an anti-aircraft role as well. The first Iowa-class ship was laid down in June 1940 in their World War II configuration, each of the Iowa-class battleships had a main battery of 16-inch (406 mm) guns that could hit targets nearly 20 statute miles (32 km) away with a variety of artillery shells designed for anti-ship or bombardment work. The Iowa-class battleships are the most heavily armed warships the United States Navy has ever put to sea, due to the continual development of their onboard weaponry.

USS Wisconsin, photographed at sea in her 1980s configuration.
