M321

The M321 is a 12.7 mm (0.50 BMG) machine gun developed by the U.S. Army in the late 1950s and early 1960s. It was designed as a replacement for the M2 Browning machine gun, particularly for use in aircraft and ground vehicles. The M321 was intended to be more compact, lightweight, and reliable than its predecessor while maintaining comparable firepower.

The weapon operates on a gas-operated, blowback system and fires the powerful .50 BMG cartridge, capable of penetrating armor and delivering devastating stopping power. It was initially tested in the early 1960s but was ultimately deemed unsuitable for aircraft use due to its weight and complexity. However, it was later adopted for ground-based applications, including armored vehicles and stationary defense positions.

The M321 features a distinctive design with a short, stubby barrel and a folding handle for easier handling. It was chambered for the same ammunition as the M2, ensuring compatibility with existing ordnance. Despite its potential, the M321 was never widely deployed due to logistical and operational challenges, including high maintenance requirements and limited production runs.

Today, the M321 is considered a historical curiosity rather than an active service weapon. Its development reflects the U.S. military’s efforts to modernize heavy machine guns during the Cold War era, though it did not achieve the same level of success as other contemporary designs. The M321 remains of interest to collectors and historians as an example of mid-20th-century arms development.