What is "tracer ammunition" used for with the M240?

Tracer ammunition is specifically designed to provide a visual reference during firing, allowing shooters to see the trajectory of their rounds in flight. This feature is particularly useful for making aiming adjustments in real-time, which is crucial in a combat scenario where precision is vital. The visible trail produced by tracer rounds helps in marking targets as well, enabling the shooter or supporting units to identify the target area effectively.

The use of tracer ammunition enhances situational awareness for both the shooter and their team, making coordination easier when engaging an enemy. This capability is particularly beneficial when firing at longer ranges or in low visibility conditions. The bright colored trail helps in assessing the effectiveness of fire and making necessary adjustments immediately.

While tracer rounds have other applications, such as indicating a specific point of aim, their primary role in conjunction with the M240 is related to assisting with aiming and marking targets, which is why this response is the correct one.