Tracer rounds contain flammable materials that ignite and produce a bright (but deadly) trail of light towards a target. Intended to guide the shooter during adverse conditions, they can prove to be extremely valuable during low-visibility scenarios.
Due to the fact that an enemy can potentially see where the shots are coming from, they are normally used sparingly — often distributed between several normal rounds.
A Marine Special Operations Team member fires a M240B machine gun during night fire sustainment training in Helmand province, Afghanistan.
A soldier from the District of Columbia National Guard fires tracer rounds from an M249 machine gun, during crew-served weapon night fire training.
Gunnery Sgt. Dragos Coca, from the 15th Marine Expeditionary Unit, engages targets during a desert survival and tactics course.
Soldiers from the Colorado Army National Guard fire tracer rounds from the M240B medium machine gun with the help of night optics at Fort Hood, Texas.
Soldiers fire .50-calibre machine gun rounds at the base of a training target to indicate to nearby helicopters where to fire their rockets during partnered aerial-ground integration training between US and Iraqi forces.
Marines from 2nd Battalion, 1st Marines, 11th Marine Expeditionary Unit, fire M240G medium machine guns at fixed targets in Djibouti.
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