Name a common heavy machine gun used in armed forces today.

The M2 Browning .50 caliber machine gun is a prominent heavy machine gun that has been widely used by armed forces around the world. Its design, characterized by a robust and reliable mechanism, has made it a staple in military applications since its introduction in the early 20th century. It offers significant stopping power and range, making it highly effective against both personnel and light vehicles.

This machine gun is typically mounted on vehicles, ships, or used in ground defense, showcasing versatility in various combat scenarios. Its caliber of .50 (12.7mm) allows for excellent performance in terms of penetration and lethality, which has contributed to its long-lasting presence in modern militaries. While other options listed are also firearms, they do not fit the criteria of a common heavy machine gun in current armed forces as effectively as the M2 Browning does.