Project Eldest Son

During the Vietnam War, the US government had a secret military operation called Project Eldest Son. It involved flooding communist ammo depots throughout Southeast Asia with thousands of sabotaged rifles, machine guns, and mortar rounds. Each of the ordinary-looking bullets was packed with enough high explosives to destroy any weapon that fired it while also maiming (or perhaps even killing) the unlucky shooter. Charges hidden within spiked mortar shells were powerful enough to wipe out an entire gun crew. Fake documents were also left behind that questioned the quality control in Chinese munitions factories.