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 was originally developed by NATO in the middle of the 20th century. Due to its reliability and heavy power, it is used with most common armaments in the UNSC Armed Forces. It can be regularly found in packs littered around battlefields.

The following weapons are chambered with the M118 FMJ-AP:

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

The round is effective against infantry, especially against unarmored or unshielded opponents. Energy shields drastically reduce the effectiveness of this round, as it does not have enough kinetic energy to significantly drain the shields. The round is also largely ineffective against vehicles, as it is not significantly armor-piercing. Massed fire from a squad of infantry, however, is enough to drain shields and destroy or disable most vehicles short of tanks due to the sheer number of rounds fired. Thus, this is primarily an infantryman's round for use against other infantry.

Real world background

There is more information available on this subject at 7.62×51mm NATO on the English Wikipedia.

The 7.62×51mm NATO was originally developed by NATO, a military alliance between national governments, in the middle of the 20th century. It was developed to be reliable when used in fully automatic weapons, to have a large punch, and to standardize service rifle calibers between governments, in order to improve logistics. It replaced a variety of smaller ammunition and largely achieved the goals of development.

Gallery

Packet of the M118.
Closeup of an M118 FMJ-AP cartridge in an MA5D's magazine in Halo 4.
NATO 7 62x51.jpg

Real-life 7.62×51mm NATO rounds, with a ruler and AA battery for scale.