120mm ventral gun

The 120mm Ventral Gun is a weapon mounted in pairs to the underside of the UNSC C709 Longsword-class Interceptor. It possesses at least a 90 degree swivel, and is able to be retracted into the hull. The weapon's shells are of a higher caliber than the Longsword's main weapon, the 110mm Rotary Cannon, and presumably do more damage. However, the weapon may be of a lower velocity and/or weaker munitions type, making it more effective in ground attack and close combat situations.

During the capture of the Ascendant Justice by UNSC survivors of the Battle of Installation 04, a Longsword's 120mm ventral guns were used to clear one of the vessel's hangars of a "legion" of Unggoy. The shells cut through unshielded fighters, fuel pods, and the Covenant defenders with ease.