7.92×33mm Kurz, the EM-2. A second infantry weapon was developed by Metcalf, the EM-3, but was not successful. Intermediate cartridge As the war ran down, in 1945 the Army formed the Small Arms Calibre Panel (SACP) to develop a new standard calibre for future weapons. Military intelligence suggested that it would be ten years before the Soviets would be ready for another major war, so the time frame for re-equipping was the mid-to-late 1950s. This gave the Panel ample time to test a number of options. Experience during the war led to demands for a smaller "intermediate" sized cartridge that would allow fully automatic fire from a rifle-sized weapon. The Army demanded a high degree of accuracy due to the emphasis on marksmanship, so the new round was designed to meet the performance of the .303 (7.7 mm) at but at the reduced range of . After testing a variety of designs, they selected a bullet of about calibre and long, with a mass of . With the release of the SACP reports, interest in the original series of EM weapons ended and a call for weapons based on the new round went out in September 1947. By this time, Korsak had left the original EM-1 program and Kazimierz Januszewski had replaced him and had adopted the anglicized name Stefan Kenneth Janson. Janson's new design was given the name EM-2, in spite of being more closely related to the original EM-1. A new EM-1 was developed by Stanley Thorpe while Eric Hall developed an EM-3. Perhaps due to the confusing re-use of the names, these weapons are often referred to by their designer's names, becoming the "Thorpe EM-1", "Janson EM-2" and "Hall EM-3". As if this were not confusing enough, code names were also assigned, the EM-1 "Cobra", EM-2 "Mamba", while the EM-3 did not proceed and did not receive a name, as was the case for an entry from Dennis Burney as the EM-4. Both the EM-1 and EM-2 were bullpup-style weapons; the magazine and chamber are placed behind the trigger and pistol grip, leading to a shorter overall length (by about 20%) and a better ratio between barrel length and weapon length. The overall length of the EM-2 is less than the US M14 in spite of its barrel being longer. Both EM-1 and EM-2 used 20-round magazines with "charger" reloads (the charger guide was later omitted from