EM-2

The EM-2, also known as Rifle, No.9, Mk.1 or Janson rifle, is a British assault rifle. It was briefly adopted by the British Army in 1951, but the decision was overturned very shortly thereafter by Winston Churchill's incoming government in an effort to secure NATO standardisation of small arms and ammunition. It was an innovative weapon with the compact bullpup layout, built-in carrying handle and an optical sight.
The EM-2 was designed to fire the new .280 British round, one of the first purpose-designed entirely intermediate cartridges, designed to replace the .303 round to a 1945 requirement as a result of combat experience and German advances in weapons design during World War II. It was intended to replace the Lee-Enfield bolt-action rifles and various submachine guns, while the TADEN would replace the Bren gun and Vickers machine gun.
The EM-2 was discontinued by the United Kingdom when the United States claimed the .280 British round was too weak for use in rifles and machine guns, and favoured the much more powerful 7.62×51mm NATO round, leading the British Army to adopt the FN FAL. A bullpup layout for a British service rifle was finally adopted some years later in form of...