Unidentified master gunnery sergeant

Master Sergeant Gunns was a noncomissioned officer in charge of an armory on Cairo Station. He helped the Master Chief fit into his new Mark VI armor. He was killed soon after by a squad of Elites as Covenant invaded the station.

In all likelihood, "Master Sergeant Gunns" is actually an unnamed Master Gunnery Sergeant (yes the rank exists in the Marines), since "Gunns" is never verifiably referred to by his name. Seeing as how Gunns works in a armory with equipment, has a lot of weapons, was fixing up weapons, and upgraded the MC's suit, he could certainly be a Master Gunnery Sergeant. The Marines call their Gunnery Sergeants Gunnys, and their Master Gunnery Sergeants Master Guns. Johnson called Gunns a Master Guns.

Also, Master Gunnery Sergeants and Sergeants Major (Johnson) are pretty much equals, and since Johnson and Gunns talk none of them saluted, said 'sir', or had any formals what-so-ever means that they are equals. (Although enlisted personell are forbidden to salute other enlisted personel nor are they allowed to call each other "sir" but some still do it out of respect)

He dies facing two Elites with a Shotgun on the Cairo Station.

Quotes

 * Gunns: "So, Johnson when you gonna tell me how you got back home from Halo in one piece?


 * Johnson: "Sorry Gunns, that's classified."


 * Gunns: "Pfft, my ass! Well you can forget about those adjustments to your A2 scope!"


 * Gunns: "Get outta my armory, SPLIT-LIP!


 * Gunns: "His armor's working fine Johnson, so shut your chilly-hole!"