Antipersonnel

An anti-personnel weapon is one primarily used to incapacitate people, as opposed to attacking structures or vehicles, or hunting game. The development of defensive fortification and combat vehicles gave rise to weapons designed specifically to attack them, and thus a need to distinguish between those systems and ones intended to attack people. For instance, an anti-personnel landmine will explode into small and sharp splinters that tear flesh but have little effect on metal surfaces, while anti-tank mines have considerably different design, using much more explosive to effect damage to armored fighting vehicles.

Many modern weapons systems can be employed in different roles, for example a tank's main gun can fire armor-piercing ammunition in the anti-tank role, high-explosive ammunition in the anti-structure role and fragmentation shells in the anti-personnel role.

There are also more exotic classes of weapons, such as neutron bombs, chemicals, and biological weapons, which are only designed to attack people. As there is greater international criticism of them, they are therefore rarely used. These are not generally referred to as anti-personnel weapons, but by their own names or group terms (e.g., NBC weapons) by which they are specifically banned. Such weapons often create much collateral damage and may affect large numbers of civilians.

Debate has arisen over whether some primarily anti-materiel weapons can be used as anti-personnel weapons. The Barrett M82 rifle, standardized by the U.S. military as the M107, fires a large-calibre .50 BMG round that will penetrate most commercial brick walls and concrete blocks. It is an anti-materiel rifle designated as a Special Application Sniper Rifle and designed for use against military equipment (materiel), rather than against other combatants. It is used by many armies around the world both in regular forces and in special forces units. As it uses a .50 BMG round, this has led to some debates in the U.S. armed forces about the legality of using such a large anti-materiel rifle round against a human. There have been persistent reports that some U.S. military personnel believe that the use of .50 BMG in a direct antipersonnel role is prohibited by the laws of war. However, Maj. Hays Parks states that "No treaty language exists (either generally or specifically) to support a limitation on [the use of .50 BMG] against personnel, and its widespread, longstanding use in this role suggests that such antipersonnel employment is the customary practice of nations."

...
Wikipedia