Mark 33 naval coilgun

The Mark 33 naval coilgun, known colloquially as the Spitfire, is a weapon system mounted on UNSC warships for use in close quarters combat against hostile vessels.

Specifications
The Mark 33 is a scaled-down 406mm bore Magnetic Accelerator Cannon that fires 5-ton tungsten projectiles at a velocity of 300,000 meters per second, delivering 225 terajoules of kinetic energy on impact. Despite this relative lack of "stopping power" the Spitfire can achieve a much higher rate of fire compared to a "conventional" spinal MAC, somewhat mitigating this shortcoming. This fire-rate advantage is increased by two or more Spitfires firing in tandem, with the most commonplace mounting consisting of two cannons in a rotating turret assembly. The Valiant-class is armed with turrets that mount four fire-linked cannons apiece.

History
Initially developed in 2470, the Mark 33 was originally intended solely for use by the Valiant-class battleship. However, HIGHCOM ordered that vessels of frigate and destroyer tonnage were to be armed with these weapons to increase their effectiveness in ship-to-ship combat at ranges of ten kilometers or less. During the Great War the Spitfire proved surprisingly effective against shielded capital ships, and extremely potent against unshielded ones, as shown by the battleship Bismarck during the Battle of Mantle in 2540.

During her refit in preparation for Operation: RED FLAG, the UNSC Pillar of Autumn was equipped with 40 twin-linked Mark 33 Spitfire turrets, which would be used to great effect during the Fall of Reach and the subsequent Battle of Installation 04.