At a rapid rate of fire, how often must the barrel of the M240B be changed?

The correct answer is based on the operational guidelines for the M240B machine gun, which specify the barrel change interval during sustained rapid fire to prevent overheating and ensure optimal performance. The M240B is designed for sustained fire capabilities, but when fired at a rapid rate, it generates significant heat.

To maintain proper functioning and avoid potential damage from overheating, the recommendations indicate that the barrel must be changed every 2 minutes. This interval allows for managing the temperature of the weapon effectively, prolonging its usability in combat scenarios, and enhancing safety for the operator. Following this procedure is crucial in maintaining weapon reliability and effectiveness during extended engagements.