Which famous military firearm faced a massive recall during the Vietnam War due to its tendency to jam in combat conditions, leading to a congressional investigation?

Throughout military history, equipment and weaponry development has seen both triumphs and failures. Some product failures led to catastrophic recalls that changed the course of military procurement and development. This trivia question focuses on one of the most infamous product recalls in modern military history that had significant implications for both the manufacturer and military operations.

This is a live public trivia poll on AIPolls.Net. Vote and see real-time results.

M16 rifle
M1911 pistol
M60 machine gun
M79 grenade launcher