MG FF cannon
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The MG FF was a drum-fed 20 mm aircraft autocannon developed in 1936 by Ikaria in Germany. As a derivative of the swiss Oerlikon FF F cannon the MG FF was license-produced in Germany. The MG FF was designed to be used in fixed or flexible mountings in Luftwaffe aircraft during World War II.
The weapon had some serious disadvantages such as low rate of fire (RoF) and muzzle velocity as well as limited available ammunition in its drums. Wing installation on Bf 109 and Fw 190 was not easy as the drum required substantial space thus limiting the ammunition storage to 60 shells. An ammunition drum of 90-round nominal capacity was developed for Fw 190 A-5 and retrofitted to some earlier variants. There were also experiments with belt feed.
The MG FF was adapted to fire a high explosive mine shell (Minengeschoss) that featured a projectile with thinner walls that allowed increased explosive charge. This projectile was lighter and 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. The now-called MG FF/M was introduced with the Bf 109 E-4 and Bf 110 C-4 in Summer 1940.
The MG FF and FF/M saw widespread use in fighters like Bf 109E, early Bf 109F, Bf 110 C to F and Fw 190A-2 to A-5 as well as in some bombers like Do 217, He 111 and many other aircraft. It was often replaced with the 20 mm Mg 151/20 during 1943 but saw a come-back as primary Schräge Musik gun in the Bf 110 night fighters as it perfectly fits into the rear cockpit.
The MG FF fired a 134 gram projectile with a muzzle velocity of ~600 m/s and a rate of fire of about 520 rounds per minute. The MG FF/M fired a 90 g HE/M (high explosive mine shell) projectile with a muzzle velocity of ~700 m/s and a rate of fire of ~540 rounds per minute. AP, HE and incendiary projectiles were also available (115 to 117 g projectiles, 585 m/s, ~520 rpm) because the mine-shot was not capable of holding incendiary or tracer parts.
Technical Data
- Weight : 26.3 kg
- Length : 1.37 m
- Muzzle Velocity : 600 m/s (MG FF), 585 m/s (FF/M with AP or HE), 700 m/s (MG FF/M with mine shell)
- Rate of Fire : 520 rpm (MG FF, FF/M with AP or HE), 540 rounds per minute (MG FF/M with mine-shot)
- Round types: armor piercing (AP), high explosive (HE), incendiary, all with or without tracer
- HE(M) high explosive mine-shot (only MG FF/M)
