The period was characterised by experiments by Luftwaffe units, both official and unofficial, in armament. A popular story was circulated by 2./JG 1. One of its pilot, "Leutnant" Heinz Knoke, claimed to have conducted his own experiments with a 250 kg (550 lb) bomb with a 15-second fuse. Knoke dropped the bomb from above the bombers on 22 March and claimed a B-17 was downed by the explosion. Only one B-17 fell that day to III. "Gruppe", but the OKL acclaimed Knocke's story. Attempts were made by Luftflotte 3 to send 11 bomb-carrying fighters on 16 April against US bombers over Lorient but the operation failed. Reports of these German tactics by American crews continued for year, long after the Luftwaffe had given up on them. The experiments with the under-wing WGr 21 rocket launcher proved promising but required time to develop. The interim solution was under-wing cannon to cure the Bf 109 Gs weak armament for anti-bomber combat. Photographic evidence exists that more heavily armed Fw 190 A-5s were shared between II. "Gruppe" and II. "Gruppe" of "Jagdgeschwader" 300 (JG 300—300th Fighter Wing) when both "gruppen" occupied Rheine airbase in April 1943.