From Halopedia, the Halo wiki
An armory is a military depot used for the storage of weapons and ammunition. Armories are a mainstay feature of UNSC ships and bases.
Pillar of Autumn
Halcyon-class light cruisers are known to have at least two armories; one near the Bridge and a larger one near Engineering. However, since the Autumn was heavily modified, it is unknown if standard Halcyon Cruisers are exactly the same as it.
During the crucial events of the Battle of Installation 04, the Pillar of Autumn's armories were almost completely emptied of their weaponry during a raid on the crashed ship by UNSC forces. The retrieved weapons were taken by D77-TC Pelicans to Alpha Base and distributed to the personnel. During his mission on board the Autumn, John-117 rearms in the one next to Engineering to battle the Flood and the Covenant to collapse the ship's reactor core and destroy the ring. By the finale of the battle, however, many M90 shotguns, MA5B assault rifles, M41 rocket launchers and ammunition for these weapons were still in their racks, though some weapons were scattered everywhere with no ammunition in them at all.
Large orbital space stations like the orbital defense platforms are fitted as well with at least one armory, in case of enemy boarding actions. Only one is seen onboard Cairo Station in the level of the same name. It contained a large amount of weapons, including M90 shotguns, BR55 battle rifles, M7 SMGs, and ammo. It also housed the energy shield test station used to bring the Master Chief's armor shields back online.
A 20th century base refitted for UNSC usage against Covenant invaders near Voi, Kenya. No official armory is seen inside this base, however lots of weapons are found scattered throughout the level, mainly held in racks.
The M510 Mammoth heavy ground vehicle has an weapons and ammunition rack in its internal storage bays for vehicles and weapons.
List of appearances