The 20-K is the typical Soviet rank 1 gun, players should get used to it since it will be your main armament up until rank 2. This gun has a good amount of HE filler, meaning penetrating shells will do good damage, sometimes even one-shot enemies. In longer ranges, shells begin to lose penetration and accuracy: it is not made for sniping. Try to bring ~10-15 BR-240SP (pure AP shells) for heavier targets. This gun is very forgiving to beginners since it has very fast reload speed and turret traverse.