How often should the barrel of the M249 be changed during the rapid rate of fire?

The correct frequency for changing the barrel of the M249 during rapid rates of fire is every 2 minutes. This procedure is crucial because sustaining a high rate of fire generates significant heat, which can lead to a loss of accuracy and could potentially damage the weapon if the barrel overheats. By changing the barrel at this interval, the operator helps to ensure that the M249 remains effective and functional, reducing the chances of a malfunction caused by overheating.

The rapid rate of fire is typically characterized by sustained bursts, which escalates the heat buildup. Thus, adhering to the 2-minute interval for barrel changes is a standard practice to maintain operational readiness and weapon integrity.