|Place of origin||Nazi Germany|
|Wars||World War II|
|Mass||26.3 kg (58 lb)|
|Length||1,337 mm (52.6 in)|
|Barrel length||822 mm (32.4 in)|
|Rate of fire||520-540 rpm|
|Muzzle velocity||585, 600 or 700 m/s|
|Feed system||Drum 30,45,60,90 rounds|
The MG FF was a drum-fed, blowback-operated, 20 mm aircraft autocannon, developed in 1936 by Ikaria Werke Berlin of Germany. It was a derivative of the Swiss Oerlikon FF F cannon (its FF suffix indicating Flügel Fest, for a fixed-mount, wing location from the Swiss original), with the Oerlikon FF design itself a development of the Imperial German World War I Becker 20 mm cannon, and was designed to be used in space-limited, fixed mountings such as inside aircraft wings, although it saw use as both an offensive and a defensive weapon, in both fixed and flexible format. It saw widespread use in those roles by the German Luftwaffe, particularly during the early stages of World War II, although from 1941 onwards it was gradually replaced by the Mauser firm's 20 mm MG 151/20, which was lighter, and had both a higher rate of fire and muzzle velocity.
MG FF stands for Maschinengewehr Flügel Fest, which translates into "machine gun, wing, fixed"; this reflects the fact that in Luftwaffe practice guns of 20 mm or less were designated as "machine guns" (maschinengewehr) as opposed to larger "machine cannons", or autocannons, which were "MK", for maschinenkanone. The "wing, fixed" part reflects the fact that the primary motivation behind its design was to create a 20 mm caliber weapon that was compact and light enough to be mounted in the wings of aircraft, especially fighters.
Compared to rival designs, such as the Hispano-Suiza HS.404 – which had been developed from the larger Oerlikon FF S – the MG FF had some disadvantages, such as low rate of fire and low muzzle velocity, as well as limited ammunition storage in its drums. On the other hand, it was much lighter and shorter. Even with its compact size, wing installation on the Messerschmitt Bf 109 and Focke-Wulf Fw 190 fighters was not easy, as the drum required substantial space, and as a consequence the ammunition storage was initially reduced to 60 shells per drum. An ammunition drum of 90-round nominal capacity was developed for the Fw 190 A-5, and retrofitted to some earlier variants. There were also experiments with belt feedings.
The MG FF was adapted to fire a new type of high-capacity, high-explosive "mine shell" that featured a projectile with thinner walls that allowed increased explosive charge. This projectile was lighter and thus had a higher muzzle velocity than the previous ammunition; this also entailed that it generated less recoil than earlier projectiles requiring a modification of the recoil mechanism. With this modification it could fire the new mine shell, but accidentally using the heavier MG FF ammo could damage the gun. In the interest of avoiding such errors, the weapon was redesignated the MG FF/M. It was introduced with the Bf 109 E-4 and Bf 110 C-4 in summer 1940.
The MG FF fired a 134 g projectile with a muzzle velocity of some 600 m/s and a rate of fire of about 530 rounds per minute. The MG FF/M fired a 90 g HE/M (high explosive mine shell) projectile with a muzzle velocity of c. 700 m/s and a rate of fire of c. 540 rounds per minute. AP, HE and incendiary projectiles were also available (115 to 117 g projectiles, 585 m/s, c. 520 rpm) because the mine-shot was not capable of holding incendiary or tracer parts.
The MG FF and FF/M saw widespread use in fighters such as the Bf 109 E-3 to F-1, Bf 110 C to F, and Fw 190 A-1 to A-5. Early variants of the Fw 190 (A-1 to A-5) were typically fitted with an inboard pair of MG 151 and an outboard pair of MG FF/M, although the MG FF/M were sometimes removed in the field in order to save weight. The MG FF/M fed from a 60-round drum that required an underwing bulge to fit within the wing (90 rounds in the A-5). From the A-6 onward, the MG FF/M were replaced by a pair of MG 151/20 feeding from 125 round belts, or deleted altogether. The cannon was also fitted to bombers such as the Do 217, Ju 88, He 111, Do 17, as well as many other aircraft, either as aerial defense, or more often for anti-ship and defensive fire suppression. Although the MG FF was often replaced with the 20 mm MG 151/20 from 1941 onwards, it saw a comeback in 1943 as the primary Schräge Musik gun in the Bf 110 (and other) night fighters, as it fit perfectly into the rear cockpit, and muzzle velocity was less important in this application (there were also stocks of surplus guns and ammunition to be used up).
Armor-piercing ammunition is a type of projectile designed to penetrate either body armor or vehicle armor.
The 8.8 cm KwK 36 was an 88 mm tank gun used by the German Army during World War II. This was the primary armament of the PzKpfw VI Tiger I tank. It was developed and built by Krupp.
An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bullets) fired by a machine gun. Autocannons have a longer effective range and greater terminal performance than machine guns, due to the use of larger/heavier munitions, but are usually smaller than tank guns, howitzers, field guns or other artillery. When used on its own, the word "autocannon" typically indicates a non-rotary weapon with a single barrel. When multiple rotating barrels are involved, such a weapon is referred to as a "rotary autocannon" or simply "rotary cannon".
R4M, abbreviation for Rakete, 4 kilogramm, Minenkopf, also known by the nickname Orkan due to its distinctive smoke trail when fired, was a folding-fin air-to-air rocket used by the Luftwaffe at the end of World War II.
The MK 108 was a 30 mm caliber autocannon manufactured in Germany during World War II by Rheinmetall‑Borsig for use in aircraft.
The MG 17 was a 7.92 mm machine gun produced by Rheinmetall-Borsig for use at fixed mountings in many World War II Luftwaffe aircraft, typically as forward-firing offensive armament. The MG 17 was based on the older MG 30 light machine gun, as was its defensive flexible-mount counterpart, the MG 15 machine gun.
The MG 151 was a German 15 mm aircraft-mounted autocannon produced by Waffenfabrik Mauser during World War II. Its 20mm variant, the 20 mm MG 151/20 cannon, was widely used on German Luftwaffe fighters, night fighters, fighter-bombers, bombers and ground-attack aircraft. Salvaged guns saw post-war use by other nations.
The General Electric GAU-8/A Avenger is a 30 mm hydraulically driven seven-barrel Gatling-style autocannon that is typically mounted in the United States Air Force's Fairchild Republic A-10 Thunderbolt II. Designed specifically for the anti-tank role, the Avenger delivers very powerful rounds at a high rate of fire. The GAU-8/A is also used in the Goalkeeper CIWS ship weapon system, which provides defense against short-range threats such as highly maneuverable missiles, aircraft, and fast maneuvering surface vessels. The GAU-8/A is currently produced by General Dynamics.
The HS.404 is an autocannon originally designed and produced by Spanish/French company Hispano-Suiza in the mid-1930s. 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 cannon is also referred to as Birkigt type 404, after its designer Marc Birkigt and later versions based on British development are known as 20 mm Hispano.
The MG 131 was a German 13 mm caliber machine gun developed in 1938 by Rheinmetall-Borsig and produced from 1940 to 1945. The MG 131 was designed for use at fixed, flexible or turreted, single or twin mountings in Luftwaffe aircraft during World War II.
The 2-pounder gun, officially designated the QF 2-pounder and universally known as the pom-pom, was a 40-millimetre (1.6 in) British autocannon, used as an anti-aircraft gun by the Royal Navy. The name came from the sound that the original models make when firing. This QF 2-pounder was not the same gun as the Ordnance QF 2 pounder, used by the British Army as an anti-tank gun and a tank gun, although they both fired 2-pound (0.91 kg), 40-millimetre (1.6 in) projectiles.
The FF were a series of 20mm autocannon introduced by Oerlikon in the late 1920s. The name comes from the German term Flügel Fest, meaning wing mounted, fixed, being one of the first 20mm guns to be small and light enough to fit into a fighter aircraft's wing. The FF series inspired many 20mm cannon used in World War II, including the Hispano-Suiza HS.404, the German MG FF, and the Japanese IJNAS's Type 99 cannon.
The Type 97 automatic cannon is a 20-millimeter (0.79 in) Japanese anti-tank rifle that began development in the 1930s. It was used by the Imperial Japanese Army (IJA) during the Second Sino-Japanese War, the Soviet–Japanese border conflicts and the Pacific War. Ever-greater thicknesses of armour on tanks rendered the Type 97 obsolete by about 1942.
The Oerlikon 20 mm cannon is a series of autocannons, based on an original German Becker Type M2 20 mm cannon design that appeared very early in World War I. It was widely produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II, and many versions are still in use today.
Breda-SAFAT was an Italian weapons manufacturer of the 1930s and 1940s that designed and produced a range of machine-guns and cannon primarily for use in aircraft. Based on the M1919 Browning machine gun, the Italian guns were chambered to fire indigenous ammunition with 7.7 mm (0.303 in) and 12.7 mm (0.500 in) calibres, predominantly ball, tracer for the 7.7mm, including high explosive incendiary tracer (HEI-T), or armour-piercing (AP) for the 12.7mm.
The Type 99 Mark 1 machine gun and Type 99 Mark 2 machine gun were Japanese versions of the Oerlikon FF and Oerlikon FFL autocannons respectively. They were adopted by the Imperial Japanese Navy (IJN) in 1939 and served as their standard aircraft autocannon during World War II.
A mine shell, also known as High-Explosive, High-Capacity (HEHC) in british military nomenclature, is a military shell type characterized by thin shell walls and a correspondingly high payload of explosives. The shell type was originally developed during the mid to late 1800s against fortresses prior to rebar but got a new role during World War II against air targets as reinforced fortresses had made the original use of the type obsolete around World War I.
The Afanasev Makarov AM-23 is a Soviet designed aircraft autocannon that has been used in a number of aircraft in the Soviet Air Force. Its GRAU index was 9-A-036. It was often used in place of the earlier and slower-firing Nudelman-Rikhter NR-23.
The 8.8 cm SK C/35 was a German naval gun used in World War II.
The 37 x 145 mmR was a series of rimmed-case, fixed-ammunition cannon shells for use in the 37mm Browning M4 autocannon.