Which of the following is NOT a feature of the M2 .50 cal?

The M2 .50 cal machine gun is renowned for several key features, each contributing to its effectiveness on the battlefield. When considering lightweight design, it's important to understand that the M2 is actually quite heavy and robust, designed to handle substantial recoil and provide durability during extensive use. This characteristic makes it less mobile and less suited to situations where a lightweight weapon would be more advantageous.

In contrast, its high muzzle velocity allows for greater accuracy over longer distances, and its long effective range enhances its versatility as both a ground and aerial weapon. Additionally, the air-cooled operation allows the gun to function reliably without the need for a water jacket, which contributes to its ease of use and deployment in combat scenarios.

Thus, the lightweight design is not a feature of the M2 .50 cal, as the weapon is known for its heavier framework which is vital for its role and capabilities.