surrounding the lagoons and swamps to expose Soviet infantry. The group claimed the destruction of 427 small boats. The Soviets abandoned attempts to negotiate the region on 4 July. Nine Ju 87s were reported as destroyed and another two damaged; 9 crew were killed, one wounded and two missing. From 1943, the large numbers of T-34 medium tanks created an urgent need for heavier aerial weapons to destroy them. The German aircraft industry failed to produce a replacement for the Ju 87, which forced its continued use with new weapons. The BK 3,7 cannon was introduced which operated on a remote pneumatic system rather than an electrically sighted mechanism. The weapon showed promise as an armour-piercing system. The muzzle velocity was 855 metres per second firing a 1.4 kg, 18 tungsten-cored explosive shell. It could penetrate 58 mm of armour at a 60 degree angle of impact at a range of 100 metres and 95mm armour could be penetrated at a range of 600 metres at a 90 degree horizontal trajectory. Further improvements allowed for penetrations of 140 mm of armour at the same range. The weight of the weapon required the wing to be strengthened which led to the Ju 87G-2. StG 2 were involved in loaning their experienced pilots to test the new Ju 87G. Hans-Karl Stepp [commander of StG 2 for the final 18 days of its existence] and Hans-Ulrich Rudel tested the new types. The Experimental Tank Fighting Unit went into battle near Bryansk on 18 March 1943 and accounted for a large number of the 116 Soviet tanks destroyed. Andreas Kuffner and Rudel became well-known and successful tank-busters on Ju 87Gs. In late June and early July 1943, StG 2 moved north to the Kharkov region in preparation for Operation Citadel, the Battle of Kursk. Ernst Kupfer took command of the wing, effective from 13 March 1943. Stab./StG 2 moved to Kharkov-East and was followed by I./StG 2 on 4 July. The group reported 37 Ju 87s on 1 July. II./StG 2 moved to Kharkov-North on 5 July under the command of Hans-Karl Stepp [from 17 June 1943] with 36 Ju 87s. III./StG 2 joined Stab. and I./StG 2 at Kharkov-East with 35 Ju 87s reported on 1 July 1943. StG 2 was engaged in the massive air battles on the southern sector. On 5 July it lost six Stukas. With StG 77, it flew