An Overview of .50 BMG Ammunition Types
The .50 Browning Machine Gun (BMG) cartridge, designated 12.7x99mm NATO, is one of the most successful and long-serving cartridges in military history. Its longevity is largely due to its power and the incredible versatility offered by its wide array of ammunition types. Each type is designed for a specific purpose, turning a weapon system like the M2 machine gun or a Barrett sniper rifle into a multi-role tool capable of engaging a vast range of targets. This overview covers the most common and significant types of .50 BMG ammunition.
General Purpose Ammunition
These rounds form the backbone of .50 caliber ammunition logistics and are used for a wide variety of common tasks.
M33 Ball
The M33 Ball is the standard, general-purpose round for the .50 BMG. It consists of a full metal jacket surrounding a soft steel or lead core. It is primarily used for training, suppressive fire against enemy positions, and engaging unarmored targets like light vehicles, personnel, and materiel. While powerful, it has limited capability against any form of armor plating.
M17 Tracer
The M17 Tracer round has ballistic properties nearly identical to the M33 Ball, but it contains a small pyrotechnic charge in its base. This charge ignites upon firing and burns brightly for over 1,500 meters, allowing the gunner to visually track the bullet’s trajectory to the target. This aids in aiming and directing fire. Tracers are commonly linked in ammunition belts in a specific ratio with other rounds, such as one tracer for every four Ball rounds (4:1 mix), to provide a constant reference for the stream of fire.
Armor-Piercing Ammunition
This family of ammunition is specifically designed to defeat hardened targets, from armored vehicles to concrete fortifications.
M2 Armor-Piercing (AP)
The M2 AP is the basic armor-defeating round. It replaces the soft core of the Ball round with a hardened steel penetrator. This simple change allows the bullet to punch through light armor plate, engine blocks, and concrete walls that would stop an M33 Ball round. It is a significant step up in capability for engaging protected targets.
M8 Armor-Piercing Incendiary (API)
The M8 API enhances the M2 AP by adding a secondary effect. It includes an incendiary chemical composition in the tip of the projectile. Upon striking a hard target, the round first penetrates with its hardened core, and the impact force then ignites the incendiary material. This is particularly effective for starting fires in engine compartments or igniting fuel and ammunition stores within a target.
M20 Armor-Piercing Incendiary Tracer (APIT)
The M20 APIT combines the functions of three rounds into one. It has a hardened steel core for armor penetration, an incendiary tip for starting fires, and a tracer element in the base for observation of fire. This makes it a highly effective and popular round for anti-aircraft and anti-vehicle use, as it allows the gunner to walk their armor-piercing, fire-starting rounds onto a moving target.
M903 Saboted Light Armor Penetrator (SLAP)
The M903 SLAP represents a major leap in anti-armor capability. It is a “sub-caliber” projectile, meaning the actual penetrator is smaller than the barrel’s bore. A small but extremely dense tungsten penetrator is held in a lightweight plastic sleeve called a sabot. This design allows the projectile to be fired at a much higher velocity than conventional rounds (approximately 4,000 ft/s). After leaving the barrel, the sabot falls away, and the hyper-velocity penetrator continues to the target. This extreme speed gives SLAP significantly greater armor penetration than any other .50 BMG round, making it effective against the armor of some infantry fighting vehicles.
Specialized and Multi-Purpose Ammunition
These rounds are designed for high-value targets and combine multiple effects into a single, complex projectile.
Raufoss Mk 211 Mod 0
Often called a “multi-purpose” or “high-explosive incendiary armor-piercing” (HEIAP) round, the Mk 211 is one of the most capable .50 BMG projectiles. It is engineered to create maximum damage through a sequence of effects. Upon impact with a hard target, a tungsten carbide penetrator in the tip provides initial penetration. This impact also ignites a zirconium powder charge for an incendiary effect and initiates a fuze for a small high-explosive charge. The round is designed to penetrate a light target, set it on fire, and then explode inside. It is highly effective against high-value targets like helicopters, radar equipment, and parked aircraft.