The weapon was developed as a private venture by the company in 1940 and was submitted to the Reichsluftfahrtministerium (RLM—Reich Aviation Ministry) in response to a 1942 requirement for a heavy aircraft weapon for use against the Allied heavy bombers appearing over German-controlled regions by then. Testing verified that the autocannon was well-suited to this role, requiring on average just four hits with its 85g RDX-load (in a 330g shell) and a resulting strongly brisant high-explosive ammunition, to bring down a heavy bomber such as a B-17 Flying Fortress or B-24 Liberator, and just a single "shattering" hit to down a fighter. In comparison, the otherwise excellent 20 mm MG 151/20 (3g of HE in 57g shell) required an average of 25 hits to down a B-17.