Mauser MG FF

Mauser MG FF
Name	Mauser MG FF
Type	20 mm aircraft cannon
Origin	German Reich
Designer	Ernst Heinkel (note: design adapted by Mauser Werke)
Design date	1932–1935
Manufacturer	Mauser Werke, subcontractors
Produced	1935–1943
Weight	24 kg (empty), varies by mounting
Length	1,170 mm
Cartridge	20×80RB mm
Caliber	20 mm
Action	Blowback with muzzle booster
Rate	520–540 rounds/min (nominal)
Velocity	600–650 m/s (varied by load)
Feed	60-round drum magazine
Sights	Fixed or aircraft gun-sight integration

Mauser MG FF

The Mauser MG FF was a German 20 mm autocannon widely fitted to Luftwaffe fighter and bomber aircraft in the 1930s and early World War II period. It served as a standard wing and fuselage gun on multiple Messerschmitt Bf 109 and Heinkel He 111 variants before being partially supplanted by larger-caliber designs such as the Mauser MG 151 and the MG 151/20. The MG FF's compact profile and drum feed made it suitable for tight wing installations, while its development reflected interwar competition among Mauser Werke, Rheinmetall-Borsig, and other German arms firms.

Development and design

Development began in the early 1930s when Reichsluftfahrtministerium procurement favored high-velocity autocannons for aircraft armament; Mauser Werke adapted a blowback concept into the MG FF to meet requests from firms like Daimler-Benz and Ernst Heinkel GmbH. The design used a simple long-recoil/blowback mechanism augmented by a muzzle booster to permit a shorter receiver, helping fit into slim wing bays on the Messerschmitt Bf 110 and Junkers Ju 88. Integration work with Lufthansa-adjacent engineering teams and testing at facilities in Peenemünde and other Luftwaffe test centers refined the feed and barrel life, though early trials highlighted sensitivity to ammunition pressures that later influenced ordnance changes.

Technical specifications

The MG FF fired 20×80RB cartridges from a 60-round drum magazine with a cyclic rate around 520–540 rounds per minute, though practical burst rates were lower in combat to manage overheating. The muzzle velocity varied with projectile load, typically 600–650 m/s for standard high-explosive incendiary rounds. The weapon weighed approximately 24 kg empty and measured about 1,170 mm in overall length, dimensions that facilitated installations in wing roots on aircraft such as the Messerschmitt Bf 110 and fuselage mounts on prototypes from Focke-Wulf. Construction incorporated steel receiver parts and chrome-lined barrels; the action relied on a combination of momentum and gas augmentation via a tuner at the muzzle to increase effective recoil energy capture.

Operational history

The MG FF entered service in the mid-1930s aboard frontline types including early Messerschmitt Bf 109 E fighters, Arado Ar 68 derivatives, and variants of the Heinkel He 112 used by export customers. It saw extensive service during the Spanish Civil War with aircraft delivered to Nationalist Spain and during the opening campaigns of World War II over Poland, Norway, and the Battle of France. As the war progressed, the MG FF was gradually replaced in many roles by the higher-performance Mauser MG 151 and the hardened MK 108 in Luftwaffe fighters, though it persisted in secondary types and as an armament of captured and export airframes throughout 1940–1942. Field units adapted drum capacities and mounting kits under the supervision of ordnance depots and regional depots linked to Heereswaffenamt directives.

Ammunition and ordinance variants

Ammunition evolution was central to the MG FF's utility. Early service rounds included light high-explosive incendiary (HEI) and armor-piercing (AP) projectiles in 20×80RB form. The MG FF/M upgrade (often associated with Mauser and ordnance engineers) introduced a larger 20×82RB cartridge to allow heavier mine and percussion-fuzed shells, increasing destructive effect against aircraft skin and light armor. Specialized rounds such as mine shells with thin walls and larger bursting charges were trialed to counter robust Royal Air Force and Soviet Air Force designs. Drum-fed belts and modified feed lips were developed for different shell lengths, and tracer loads from firms like Polte-Werke aided aiming and ballistic assessment.

Modifications and derivatives

The most notable derivative was the MG FF/M, which accepted the larger 20×82RB "Mine" rounds and required only modest receiver alterations while offering a significant increase in payload. Experimental twin and synchronized fuselage installations were tested with mounting plates by Heinkel and Messerschmitt design teams, and some ground- and sea-based adaptations were trialed by coastal units cooperating with Kriegsmarine shore batteries. Competing designs such as the Mauser MG 151 family and the Rheinmetall-Borsig MK 101 prompted incremental MG FF improvements in feed reliability and barrel metallurgy, though the airframe trend toward centrally-mounted cannons reduced wing-cannon demand.

Combat performance and evaluation

Operational feedback praised the MG FF for compactness, ease of installation, and destructive potential with mine shells, attributes noted in after-action reports from units in France and Norway. Criticisms centered on limited muzzle velocity versus some contemporaries, sensitivity to ammunition pressure variations, and relatively short barrel life under sustained firing; these issues were recorded by maintenance commands and technical branches linked to Luftwaffe logistics. Against early-war bombers and fighters the MG FF proved effective in short bursts, but as opposing aircraft became more heavily built and armored, the need for higher-velocity, higher-penetration weapons accelerated adoption of the MG 151/20 and the MK 108, relegating the MG FF to secondary roles and export markets.

Category:20 mm artillery Category:Luftwaffe weapons