 A board of inquiry found that the problem was a lack of buoyancy, a malfunctioning wave plate, and a technical problem with the drain pump, all of which are to be corrected in the new design.The two-man turret on the K21 is armed with an S&T Dynamics K40 40 mm cannon capable of firing APFSDS, high-explosive, smoke and multipurpose munitions, and a 7.62 mm machine gun.This is combined with an advanced fire-control system and gun stabilizer usually found on third-generation main battle tanks that makes the K21, together with the German Puma, able to move and engage the targets with high degree of accuracy at the same time.