Under emergency conditions, at what maximum distance should Cartridge 5.56mm, tracer, M856 be used in the M16A1?

The maximum distance for the use of the Cartridge 5.56mm, tracer, M856 in the M16A1 under emergency conditions is 90 meters. This is primarily due to the design and intended use of the tracer round, which is meant to provide visual feedback for aiming and adjusting fire. At greater distances, the effectiveness of the tracer diminishes as wind, angle, and other factors can significantly affect its trajectory and visibility.

Using the tracer round beyond this range could lead to a risk of inaccurate targeting and potential unintended consequences. Therefore, adhering to this distance ensures greater control and effectiveness in combat scenarios, maintaining both the safety of friendly troops and the effectiveness of engaging targets.