How often must you change the barrel when firing the M249 AR at a rapid rate of fire?

The M249 Automatic Rifle is designed for sustained and rapid fire in combat scenarios, but it can become overheated during extended use. When firing at a rapid rate, specifically, the recommended practice is to change the barrel every 2 minutes. This frequency is crucial because a hot barrel can lead to decreased accuracy, increased risk of barrel warping, and potential malfunctions due to overheating. By adhering to this guideline, operators can ensure their weapon remains in optimal operating condition, maintaining effectiveness during sustained engagements. This practice helps to protect the integrity of the rifle and enhances the safety and reliability of the operation.