In 1944, the British General Staff issued a specification for a new submachine gun to replace the Sten. It stated that the new weapon should weigh no more than six pounds (2.7 kg), should fire 9×19mm Parabellum ammunition, have a rate of fire of no more than 500 rounds per minute and be sufficiently accurate to allow five consecutive shots (fired in semi-automatic mode) to be placed inside a one-foot-square (30 cm × 30 cm) target at a distance of .