|Country of Origin: United States|
|Weapon Type: Select-Fire Assault Rifle|
|Fire Modes: |
|Ammunition: 5.56×45mm NATO|
|Feeding System: 30-45 Round Magazine|
|Affiliation(s): Aeran Pierce|
The Colt M4A1 Carbine labelled simply as the "Assault Rifle" in the dossier, is a select-fire assault rifle/carbine designed and developed in the United States. It is the primary weapon in the BlackSite: Area 51. It can be found plentifully nearly everywhere and its versatility allows it to be used in most situations.
As the game begins, the player through the eyes of Aeran Pierce is issued an M4A1 Carbine with a holographic sight and handguard mounted picatinny rail system for various accessories. It also comes equipped with a holographic sightallowing for a decent level of zoom and dual magazine system housing a maximum of 45 rounds of the 5.56×45mm NATO ammunition. This allows for a very fast reload should the magazine run out in the middle of a firefight. However, this fast reload cannot be used more than once at a time and after it has been performed, it requires a regular reload before it can be used again. A good way to check if the fast reload is available is if the second magazine is visible on the left side of the weapon. If the fast reload has already been performed, the player can choose to manually reload to reset the magazines, allowing for it again. Manual reloads always use the regular speed; the fast reload occurs automatically when the first magazine runs out.