How many rounds can trigger a hot barrel condition in the M249?

The correct answer is based on the understanding of the M249's barrel overheating conditions. The M249 machine gun can experience a hot barrel condition when it is fired at a high volume over a short period. Specifically, the threshold for determining that the barrel has reached a hot condition is firing 200 rounds in 2 minutes.

This standard is important because overheating can affect the accuracy and reliability of the weapon, potentially causing malfunctions such as cook-offs or barrel damage. The definition of a hot barrel is tied to the need for effective cooling and maintenance practices during sustained fire.

The other choices do not meet the established criteria for what constitutes a hot barrel condition in the M249, either by underestimating the number of rounds fired within the time frame or not adhering to the necessary sustained rate of fire that leads to overheating. Hence, the 200 rounds in 2 minutes properly indicates the threshold for reaching a hot barrel condition. Understanding this helps in both operational effectiveness and weapon safety.