halo 4's rail gun

343 Industries has pulled back the cloak or secrecy on a few new Halo 4 tidbits, revealing two somewhat significant changes.
First up is a new weapon that’s been added to the arsenal. Bow down now, to the Asymmetric Recoilless Carbine-920, or the Rail Gun as us common folk will call it.
This beast, pictured below, 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.” In other words, stay out of its sights