As completed, "Jackal" had a main gun armament of six QF Mark XII guns in three twin mountings, two forward and one aft. These guns could only elevate to an angle of 40 degrees, and so were of limited use in the anti-aircraft role, while the aft mount was arranged so that it could fire forwards over the ship's superstructure to maximise the forward firing firepower, but was therefore incapable of firing directly aft. A short range anti-aircraft armament of a four-barrelled 2 pounder "pom-pom" anti-aircraft mount and eight .50 in machine guns in two quadruple mounts was fitted, while torpedo armament consisted of ten torpedo tubes in two quintuple mounts.