It was widely used as an aircraft, naval and land-based weapon by French, British, American and other military services, particularly during World War II.

The Becker introduced the advanced primer ignition blowback (API) design for autocannons, a concept that was quickly taken up by other companies.

Shortly after production began, the Hispano-Suiza and Oerlikon companies disagreed over patent rights and their business connection came to an end.

In 1940, Hispano-Suiza was developing a belt-feeding system, as well as derivatives of the HS.404 in heavier calibres such as 23 mm but these projects were halted with the German occupation of France.

[6] The experience of the Battle of Britain had shown the batteries of eight rifle-calibre M1919 Browning machine guns to be inadequate and prompted the adoption of autocannon armament for the primary portion of RAF fighters.

The early trial installations in the Hawker Hurricane and Supermarine Spitfire had shown a tendency for the gun to jam during combat manoeuvres, leading to some official doubt as to the suitability of cannon as the sole main armament.

[7] A suitable belt-feeding system was developed by Martin-Baker and the new design was adopted by the RAF and Fleet Air Arm in 1941 in a slightly modified form as the Hispano Mk.II.

Four cannons replaced the eight Browning machine guns in the Hurricane and in some tropical versions of the Spitfire, becoming standard armament in later fighters.

The shorter barrel meant that the weapon could be housed within the wing of a fighter plane, reducing drag and making the gun less vulnerable to freezing and mechanical stress.

The British version was also licensed for use in the United States as the M1, with the United States Army Air Corps (USAAC) and U.S. Navy, which concluded that a single HS404 is analogous to three .50 machine guns in firepower while weighing less than twice as much, planning to switch to the 20 mm calibre as soon as the gun could be produced in sufficient numbers.

When delivered, the guns proved to be extremely unreliable and suffered a considerable number of misfires due to the round being lightly struck by the firing pin.

British wing-mounted fighter weapons by this period were cocked on the ground by the aircraft armourers before flight, the pneumatic cocking mechanism used previously being regarded as unnecessary weight and detrimental to aircraft performance; any stoppage in flight made the gun unusable until it could be cleared on the ground.

As late as December 1945 the U. S. Army Chief of Ordnance was still attempting to complete additional changes to the design to allow it to enter service.

After the war the United States Air Force (USAF) adopted a version of the M3 cannon as the M24, similar in most respects except for the use of the addition of electrical cocking, allowing the gun to re-cock over a lightly struck round.

[9] The problems of the American weapons led to most U.S. fighters being equipped with the AN/M2 .50 cal Browning light-barrel machine gun throughout the war.

[15] After the war, the Hispano variants disappeared fairly quickly as fighter armament due to the introduction of revolver cannon, based on the prototype versions of the un-built German wartime Mauser MG 213 design.

[17] The AN/M3 was developed into the Mk12 Colt 20 mm automatic cannon, one of the main weapons on boats of the Mobile Riverine Force in the Vietnam War and also used on some larger amphibious ships.