1,1 inch/75 Mk.1 (28 mm)

The 1.1"/75 caliber gun was an American anti-aircraft weapon of World War II, used by the United States Navy. The name means that it had a diameter of 1.1 in (28 mm) and barrel caliber of 75 (1.1 inches × 75 = 82.5 in (2.1 m)). The gun was designed to replace the M2 Browning and four barrels were required to duplicate the rate of fire. The first shipboard installation in 1939, was quickly nicknamed the Chicago Piano, possibly because it was the size of a baby grand piano and looked a little like a baby grand without its lid (although the reminiscences of the sailors who served with these guns all agree on the nickname, no one seems to know where it originated).

By 1941, these guns had been mounted on destroyers, cruisers, battleships, aircraft carriers, and some auxiliary ships. Nearly a thousand guns had been produced before production shifted to more reliable shipboard anti-aircraft machine guns in 1942. Quantities were minimal; one mount for a destroyer, two mounts for pre-1930s, and four mounts for North Carolina and newer battleships. On at least some ships they were director-controlled.

Medal of Honor: Pacific Assault

1.1 inch/75 Mk.1 appears on USS West Virginia. The player uses this anti-aircraft gun to repel aircraft attacks during the attack on Pearl Harbor. The gun has a high rate of fire, but low accuracy. Usually the plane can be shot down with 1-2 hits. just like Bofors automatic cannon, it's mostly required your skills and tracking ability in order take accurate fire and hit.

1,1 inch75 Mk.1 (28 mm) in the Medal of Honor: Pacific Assault.

First-person.

Trivia

• Gunner on anti-aircraft guns indicates which side is approaching aircraft.
• In reality, this 1.1-inch anti-aircraft gun was never installed on the USS West Virginia. Instead, the Navy opted to bring back 3-inch AA guns due to the rapidly deteriorating relationship between the US and Japan, as the military expected a conflict was imminent, The production of the 1.1-inch AA guns was not fast enough to equip the ship. Even if the 1.1-inch guns had been installed, they would not have been placed on the middle topside deck of the 5-inch/51-caliber gun casemates on the port and starboard sides. That space was already occupied by 8 of the 5"/25 dual-purpose guns, with 4 guns per side, The only locations available for the 1.1-inch AA guns would have been on the main deck at the bow and stern, with 2 guns per side.