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M555 Gauss cannon

From Halopedia, the Halo wiki

This article is about the model introduced in Halo 5: Guardians. For the model introduced in Halo 2, see M68 Gauss cannon.
M555 Electromagnetic Launcher
Production overview


Misriah Armory[1]


Ammunition type:

25×130mm M485 HV/FTHPP[1]

Feed system:

9 rounds
Unlimited (in-game)

Rate of fire:


Service history

In service:

Post-Covenant War conflicts


The M555 Electromagnetic Launcher (M555 EL),[1] known simply as the Gauss cannon is a portable turret in use by the UNSC Armed Forces, specialized ONI units, and private corporations such as Liang-Dortmund after the Human-Covenant War.[2]


The M555 Electromagnetic Launcher (then known as the X555 Electromagnetic Launcher Advanced Technologies Testbed) was first tested in classified operations during the Requiem Campaign, utilizing a hybrid of existing technologies and Covenant-derived pulsed power systems. The implementation of the new asynchronous linear-induction motor and rail channels has proven itself in testing, and development costs has stayed within budget,[1] though its precise mechanisms remain highly classified.[3] Even with the new additions, the coilgun has seen little improvement in armor penetration from its predecessor, the M68 Gauss cannon. Misriah Armory promises that up-scaled versions of the new coilguns suitable for installation on armored vehicles and aerospace vehicles will conclusively prove the value of moving to a new architecture.[1]


  • ONI Gauss Turret: Produces lingering area-of-effect damage.

REQ Card - Gauss Turret ONI.png


When detached, the M555 is loaded with 9 slugs. Carrying the turret decreases the player's speed and maneuverability to the point where he/she is invisible on the motion tracker unless the weapon is fired. Look speed is also drastically increased in comparison to other weapons.


List of appearances[edit]