M66 light railgun

From Halopedia, the Halo wiki

(Redirected from LRG Rail Gun)
For the infantry weapon, see ARC-920 railgun.
M66 light railgun
A Cobra sporting twin M66 railguns.
Production overview


Light railgun


Ammunition type:

30mm shells

Service history

In service:

Human-Covenant War


The M66 light railgun (M66 LRG) is an anti-vehicle railgun weapon system employed as a heavy munition in the Colonial Military Authority (CMA) and United Nations Space Command (UNSC).[1][2][3]


Design details[edit]

The M66 LRG is a powerful anti-armor weapon that fires 30mm high-density ferrous projectiles at ultra-high velocity. The velocity of these projectiles allows them to penetrate armor at extreme range and with superior penetration to the M512 90mm SBHV cannon used by the M808 Scorpion.[1][4][5] The M66 has a power draw of 8 megajoules.[6][4][Note 1]

Though the weapon performs similarly to Gauss cannons such as the M68 model, the M68 is a coilgun, which operates on different principles from those of a railgun.


The M66 railguns are most notable for their twin installment in the turret of the SP42 Cobra, allowing the vehicle to serve as an agile tank-hunter and anti-fortification vehicle.[3] They are mounted on the Cobra alongside the larger and more powerful M98 105mm light railgun.[1][2][3] M66's may also be installed as an optional anti-vehicle mounting in the M5 Talos automated turret system installed on prefabricated bases.[6]

When twin-mounted on the SP42 Cobra and on automated turrets, each weapon is fired alternatively, as the energy required to fire both railguns together is beyond what the platform is capable of producing. This alternating also improves the weapon's rather low rate of fire, maintaining more consistent power output.[5]


List of appearances[edit]


  1. ^ While page 43 of the Halo Wars: Official Strategy Guide describes the M66 has having a draw of 16MJ, it also describes the larger and more powerful M98 as having a power of 8MJ. On page 30 while describing the base turret weaponry, the M66 is identified as having a draw of 8MJ. The numbers shown on page 43 are presumably an error.