The Korsak EM-1 was a bullpup automatic rifle designed by Polish engineer Roman Korsak.
After the Second World War, the British Army commissioned new prototypes to be submitted for trials for adoption with the army. Four groups were set up to achieve this, each creating a different rifle. The first to be completed was the Korsak EM-1, which was designed by a Polish engineering team in Hertfordshire, headed by Roman Korsak. The Korsak rifle was chambered for 7.92x57mm rounds and the design of the weapon owed a lot to the German FG 42. It was intended to be used in conjunction with another prototype, the Taden gun, which was designed to replace the Bren gun. After Roman Korsak left the team, the project was headed by Stefan Janson. Nothing became of either the Korsak rifle or the Taden gun, and by 1947 the remaining prototypes of the Korsak EM-1 were archived. The Korsak rifle was succeeded by Stanley Thorpe's EM-1, which was also rejected. The weapon is still in existence, in the hands of the Armament Research Services in the United Kingdom.