What is the time requirement for changing the barrel under rapid rate of fire for the 240?

The correct response identifies that changing the barrel of the M240 is crucial under rapid fire due to the heat generated during operation. The recommended time requirement for barrel changes in a high-rate firing scenario is every 2 minutes. This is essential to prevent overheating, which can lead to malfunctions or damage to the weapon. Under sustained firing conditions, the performance and reliability of the M240 depend on maintaining barrel integrity, making timely changes vital.

The other options do not align with the operational guidelines established for the M240. A 5-minute change would not be sufficient considering the rapid heat buildup. Allowing 10 or 15 minutes would significantly increase the risk of overheating, potentially compromising the weapon's effectiveness and safety during combat scenarios. Hence, the 2-minute interval is designed to ensure optimal performance and longevity of the weapon under stress.