ALI-50 110mm autocannon

The 110mm rotary cannon, also known as simply "the Rotary", is a air-to-air projectile weapon utilized by the United Nations Space Command's C709 Longsword.

Design details
The weapon takes the form of a large rotary cannon, capable of firing 110mm depleted uranium shells and an extremely high rate of fire.

Usage
The 110mm is employed on the C709 Longsword, a massive space fighter used for interception and bombing. It was still employed as late as the Fall of Reach in late 2552, where it was regarded as "hopelessly archaic" in comparison to the plasma weaponry employed by the Seraph fighters used by the Covenant.

Trivia
The canonicity of this weapon is dubious; a 110mm gun would be larger than the 90mm tank cannon employed on the Scorpion, and ludicrous if employed as part of a rotary cannon. It is possible that the 110mm figure established in Halo: First Strike was the result of a typographical error (something repeated in other Eric Nylund stories such as the relativistic Magnetic Accelerator Cannons in Halo: The Fall of Reach or the "four-forty" in Halo: Ghosts of Onyx), or may have been intended to refer to the total diameter of the weapon's full assembly rather than the ammunition. This fact was supported by Robert McLees, who described the idea of "110mm rotary cannons in fighter/bombers" (as stated in the Halo Story Bible) as an example "bad crazy" in the Halo universe.

However, the number remains unchanged in the 2010 reprint of Halo: First Strike, and its validity is reinforced in Halo: The Essential Visual Guide, which states the C709 variant of the Longsword is equipped with a "heavy rotary cannon".

List of appearances

 * Halo: Combat Evolved
 * Halo: First Strike
 * Halo 2
 * Halo: Combat Evolved Anniversary
 * Halo 2 Anniversary