What component enhances the range of the M2 .50 cal weapon system?

The heavy barrel is a key component of the M2 .50 caliber machine gun that significantly enhances its effective range. A heavy barrel is designed to withstand the heat generated during sustained fire and allows for better accuracy at longer distances due to its ability to maintain a stable point of aim. The increased mass of the barrel helps absorb heat, which minimizes the wandering effect that can occur as the barrel heats up, thereby improving overall accuracy and consistency in firing.

The other options, while they may have their own benefits, do not specifically enhance the range of the weapon system in the same direct manner. The extended magazine increases ammunition capacity but does not impact the range. The optical sight improves target acquisition and can aid accuracy, but the range itself is primarily determined by the characteristics of the weapon and its ammunition. A cooling system aids in maintaining operational capability but does not directly influence the range. Thus, the heavy barrel is the critical factor that contributes most effectively to extending the range of the M2 .50 caliber machine gun.