The weapon has infinite ammo and the added protection of the fortifications behind which it is usually found. However, the turret imposes a limited firing arc, and one is exceedingly vulnerable from the lanes that the gun is unable to cover.
During Half-Life, Gordon Freeman is able to turn it against HECU soldiers, notably in the Black Mesa Transit System.
Enemies using the M-2 are easy to kill, as they are immobile while using it. A Mk 2 Grenade or a MP5 Grenade is enough to kill the enemy manning the weapon.
Presence of the machine gun usually indicates a likely wave of enemies; the machine gun should be manned as soon as possible.
The M-2 is extremely powerful, firing five rounds in the head or chest area are required to kill a H.E.C.U Marine most efficiently. However, constant awareness is required, the player should be ready to demount from the weapon as soon as they are overrun or attacked from behind.