What type of ammunition is M856?

The M856 ammunition is classified as tracer ammunition. Tracer rounds are designed with a pyrotechnic composition that ignites during flight, leaving a visible trace of light behind the projectile. This feature allows the shooter to visually track the trajectory of the round, making it useful for adjusting aim and providing fire support, particularly in low-light conditions.

Tracer ammunition serves multiple purposes, including enhancing marking capabilities for training and targeting and facilitating communication of fire direction amidst chaotic battle environments. The M856 specifically is used primarily in conjunction with the M16 rifle and M4 carbine, indicating its role in standard rifle applications where understanding the projectile's flight path is essential for effective engagement of targets.

This type of ammunition is distinct from the other options listed since dummy rounds are used for training without live ammunition, ball rounds are standard live ammunition designed for target shooting, and blank rounds simulate firing without a projectile, primarily for training or ceremonial purposes. Each of these types serves a different role within military training and operations.