Asymmetric Recoilless Carbine-920

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The Asymmetric Recoilless Carbine-920, also known as the ARC-920 or simply the Railgun, is a compact-channel linear accelerator that fires a high-explosive round at incredible speed, delivering both kinetic and explosive force to both hard and soft targets alike. This weapon has a charge time like the Spartan Laser. The railgun's charge time is approximately half of the Spartan Laser's charge time, and can be fired with only a partial charge, with the cost of reduced damage against vehicles. This weapon kills any player instantly, but does not feature a zoom. It can cause moderate damage to vehicles, and send them flying off course much like the Halo 3 Brute Shot and Halo: Reach Type-50 Directed Energy Rifle/Heavy. This weapon is currently classified as an Anti-Infantry weapon.

Although the ARC-920 lacks a zoom feature like scoped weapons, players are able to use the armor's default zoom feature midcharge to allow for increased accuracy with ranged kills.

This weapon seems to have been created in response to shielded Covenant units like Elites, Brutes and possibly Hunters. With its excellent Anti-Infantry capability, arguably surpassing that of a Sniper Rifle, it makes dealing with shielded or armored heavy Covenant infantry to be less of a tactical hassle on the battlefield.

It is possible that the ARC-920 functions by locking the slug projectile in place and charging multiple plasma armatures in the barrel to create a powerful Lorentz force. The slug would then be released, pulled forward by the magnetic force, and accelerated when passing each armature.

Trivia

 * The ARC-920 may have been inspired by the M-920 Cain Heavy Weapon from the Mass Effect trilogy.
 * The reloading animation is similar to the Concussion Rifle in Halo: Reach.
 * Despite being labeled a recoilless weapon, it appears to have a significant amount of kick when fired. This probably was done so the weapon would look more powerful.
 * Functionally, the Railgun has next to no drop when fired over long distance. However, due to lack of a scope, hitting targets at long range is dependant on the skill of the wielder.
 * This weapon has limited armor penetration; in other words, if a railgun shot hits the hatch of a Wraith or Scorpion, the shot has a high chance of killing the driver.
 * While charging, the Railgun's barrel glows blue, somewhat like the Plasma Launcher. Be wary, as this glow can be seen quite easily.
 * Though the ARC-920 is a railgun, the rounds it fires take a significant amount of time to reach its target so players may want to lead their targets unless they are at 'close to medium' range.
 * The very high damage and relatively short charge time of the railgun makes it ideal for killing Promethean Knights at close-to-medium range, especially for players attempting to complete the game on Legendary difficulty.