14.5x114mm

The 14.5 x 114mm bullet is used by the Unted Nations Space Command's Sniper Rifle System 99C-S2 AM. It was originally developed by the Soviet Union during the Twentieth Century. It was originally designed to pierce the armor of a tank, but the heavy vehichles of the Twenty-Fifth Centruy can easily withstand a strike from this round. It is one of the oldest rounds in the UNSC's armament as its use can be traced back to World War II.