M328 light machine gun
From Halopedia, the Halo wiki
The M328 light machine gun is a twin-barrelled light machine gun employed by various Human military forces. The weapon is employed on the MV-29 Wyvern gunship used by CMA Marine Corps air cavalry units, the Gao Republic Ministry of War's battle-jumpers and the UNSC Army.
- Halo Encyclopedia (2022 edition), page 156