Repulse shot down two of the four confirmed kills made by Force Z, while Prince of Wales pom-poms did record hits on enemy aircraft. The Royal Navy judged the pom-pom's effectiveness to range from about half that of the Bofors, per gun, against torpedo planes to about equal against Kamikaze attackers. It was a ubiquitous weapon that outnumbered the Bofors gun in Commonwealth naval service up to the end of World War II and it shot down many Axis aircraft. Later innovations such as Remote Power Control (RPC) coupled to a radar-equipped tachymetric (speed predicting) director increased the accuracy enormously and problems with the fuses and reliability were also remedied. The single mountings received a reprieve toward the end of the war as the 20 mm Oerlikon guns had insufficient stopping power to counter Japanese kamikaze aircraft and there were insufficient numbers of Bofors guns to meet demand. Calibre: 40 mm L/39 Shell Weight: 2 lb. (980 g) or 1.8 lb. (820 g) for High-Velocity (HV) round Rate of Fire: 115 rpm fully automatic Effective Range: 3,800 yards (3,475 m) or 5,000 yards (4,572 m) HV Effective Ceiling (HV): 13,300 feet (3,960 m) Muzzle Velocity: 2,040 ft/s (622 m/s) or 2400 ft/s (732 m/s) for HV QF 2-pounder Mark XIV The QF 2-pounder Mark XIV was the Rolls-Royce 40 mm cannon, which had been developed by Rolls-Royce as a competitor to the 40 mm "Vickers S" gun as an aircraft weapon. The latter was the more successful design, and found some use as an anti-tank weapon. A reworked version was adopted by the Royal Navy as a weapon for Motor Gun Boats, being adopted in the Fairmile C type as well as British Power Boat Company 60- and 70-foot (18- and 21-metre) type MGBs. It had a semi-automatic horizontally sliding breech block and was shipped on a manually trained pedestal mount. The weapon was not a success and of the 1,200 ordered only some 600 were delivered. It was initially replaced in various MGBs by single 20 mm Oerlikon cannon in order to make good, being ultimately succeeded in the large quick-firer role later in the war by the 57 mm Molins 6-pounder gun, the British Army's QF 6-pounder gun anti-tank gun with an auto-loader. Ammunition See also QF 1 pounder pom-pom List of anti-aircraft guns Notes References Bibliography Louis Brown, A radar history of World War II: technical and