7.62x51mm

An overview of the M118 round.

The M118 Full Metal Jacket Armor-Piercing^[1] is a 7.62×51mm rifle cartridge commonly used in the United Nations Space Command's MA5 series of assault rifles.

Overview

The M118 FMJ-AP round is the standard-issue 7.62×51mm ammunition utilised by the UNSC Armed Forces, with other options including shredder rounds. Its armor-piercing properties stem from its specially hardened construction.^[2] During the Battle of Installation 04, it was commonly found in 120-round packs in the possession of dead Marines or stockpiled on the ground wherever UNSC forces were engaged with the Covenant.

The following weapons in UNSC usage are chambered for 7.62×51mm ammunition and typically make use of M118 FMJ-AP rounds;

MA5 series assault rifles
M392 and M395 Designated Marksman Rifles
M739 Light Machine Gun
M247 General Purpose Machine Gun and M247T Medium Machine Gun

Performance

Weapons chambered for 7.62×51mm ammunition such as the MA5B assault rifle are considered to be powerful by UNSC soldiers.^[2] UNSC infantry combat armor is capable of preventing lethal penetration at close range from a limited burst,^[3] though infantry and even light vehicles or aircraft such as un-shielded Covenant Banshees are susceptible to fatal damage under sustained, accurate fire.^[4] Energy shields drastically reduce the ammunition's stopping power, as a great deal of concentrated fire from multiple weapons - or an extended period of continuous automatic fire from a single weapon - is needed to overwhelm them.^[2]

Trivia

The 7.62x51mm cartridge is an actual cartridge, and is used in several NATO machine guns.

Gallery

An M118 ammo pack in Halo: Combat Evolved.
A packet of M118 ammunition.
A 7.62x51mm bullet extracted from Zhao Heng Lopez's shoulder in The Mona Lisa.
Closeup of an 7.62x51mm AP cartridge in an MA5D's magazine in Halo 4.
A round of 7.62x51mm AP ammunition seen in its magazine in Halo 5: Guardians.