Tracer Ammunition

Tracer ammunition (tracers) are bullets or cannon caliber projectiles that are built with a small pyrotechnic charge in their base. Ignited by the burning powder, the pyrotechnic composition burns very brightly, making the projectile visible to the naked eye. This enables the shooter to follow the projectile trajectory in order to make aiming corrections.

When used, tracers are usually loaded as every fifth round in machine gun belts, referred to as four-to-one tracer. Platoon and squad leaders will sometimes load their magazines entirely with tracers to mark targets for their soldiers to fire on. Tracers are also sometimes placed two or three rounds from the bottom of magazines to alert the shooter that their weapon is almost empty.

Tracer rounds may also ignite flammable substances on contact from a nominal distance.