76 mm air defense gun M1931
76 mm M1931 at Kempele, Finland.
Type	Anti-aircraft gun
Place of origin	Soviet Union
Service history
Used by	Soviet Union Finland Nazi Germany
Wars	Winter War World War II
Production history
Produced	1931–1938
Specifications
Mass	Travel: 4,820 kg (10,630 lb) Combat: 3,650 kg (8,050 lb)
Barrel length	4.1 m (13 ft 5 in) L/55
Crew	10[1]
Shell	Fixed QF 76.2 × 558 mm. R[2]
Shell weight	6.6 kg (14 lb 9 oz)
Caliber	76.2 mm (3 in)
Breech	Semi-automatic vertical sliding-wedge
Recoil	Hydro-pneumatic
Carriage	Two-wheeled carriage with collapsible cruciform outriggers
Elevation	−2° to +82°
Traverse	360°[1]
Rate of fire	10–20 rounds per minute
Muzzle velocity	815 m/s (2,670 ft/s)
Maximum firing range	9.3 km (31,000 ft) AA ceiling[1]

The 76 mm air defense gun M1931 (Russian: 76-мм зенитная пушка обр. 1931 г.) was an anti-aircraft gun used by the Soviet Union during the Winter War and the first stages of World War II.

History

The configuration of the air defense gun M1931 owed much to the design of the contemporary Vickers 3-inch anti-aircraft guns. The Soviet M1931 like the Vickers gun had a two-wheeled carriage with collapsible cruciform outriggers.^[1]

The M1931 was replaced in production in 1938 by the 76 mm air defense gun M1938 which had a four-wheeled dual-axle carriage with two collapsible outriggers. The M1931 and M1938 had nearly identical performance and were gradually replaced by the more powerful 85 mm air defense gun M1939.^[1]

A number of M1931 guns were captured by Finland during the Winter War and were employed by them as the 76 ItK/31 ss during World War II.^[3] Likewise, M1931 guns captured by the Germans were given the designation 7.62 cm Flak M.31(r) and used until they were either worn out or their ammunition supply ran out. A few were rebored to fire German 8.8 cm ammunition and redesignated the 7.62/8.8 cm Flak M.31(r). However, the majority were scrapped in 1944.^[1]

After the war, a number of Finnish guns were converted into light coastal guns (76 ItK 31 Rt, where "Rt" stands for "rannikkotykistö" = coastal artillery) by the addition of a scope site with manual lead mechanism for direct fire against moving surface targets. These guns were still in use as training guns of the coastal artillery into the 1980s.^[4]

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