In use by 2478, the C-14 fires hypersonic 8mm 'Impaler Rounds' which can penetrate up to two inches of steel plating.
The Impaler is fully automatic with a fire rate of 30 rounds per second, although fully automatic fire is discouraged under most circumstances. A capacitor system is used to fire the weapon in short bursts, conserving ammunition and minimizing power requirements. Due to this, the C-14 rifle has high recoil; CMC armor is designed to suppress this. The armor can also supplement the rifle's power supply.
The C-14 has been used as an automatic base defense weapon, mounted on a tower.
The C-14 is capable of firing a wide variety of ammunition; armor piercing ammunition used against heavily armored targets, depleted uranium casings that encompass U-238 rounds (which are the most popular variant among marines given that they extend the rifle's range up to 25%), hollow point spread shells which flatten and expand on impact for maximum wounding efficiency, incendiary slugs used against structures, and steel tipped shells used to maim, rather than kill an enemy.
The Impaler remains accurate up to a range of 400 meters.