Messerschmitt Bf 109 11 July 1938 when Erhard Milch finally allowed Willy Messerschmitt to acquire the company. All Messerschmitt aircraft that originated after that date, such as the Me 210, were to carry the "Me" designation. Despite regulations by the RLM, wartime documents from Messerschmitt AG, RLM and "Luftwaffe" loss and strength reports continued to use both designations, sometimes even on the same page. All extant airframes bear the official "Bf 109" designation on their identification plates, including the final K-4 models. The aircraft was often referred to by the folk-designation, 'Me 109', particularly by the Allies. The aircraft was often nicknamed "Messer"
Operational history of the Luftwaffe (1939–45) fighter losses increased. The introduction of the B-17G with its remote controlled 'chin' turret forced a change of tactic on the "Jagdwaffe". Throughout 1943 head-on attacks had proved successful against American heavy bombers. Many Luftwaffe units now upgraded the firepower of their fighters. Some Fw 190 fighters carried MK 108 30 mm cannon that could destroy most heavy bombers with two or three hits. The later variants of the Messerschmitt Bf 109 (from the" Gustav" onwards) were also capable of carrying heavier armament like the MK 108, although only a single barrel firing through the propeller shaft as an engine-mounted