D-74 122 mm Field Gun

D-74 field gun
North Vietnamese Army gunners manning a D-74
Type	Field gun
Place of origin	Soviet Union
Service history
Used by	Various
Wars	Vietnam War Sino-Vietnamese War Sino-Soviet border conflict Indo-Pakistani War of 1965 Sino-Indian War Yom Kippur War Lebanese Civil War South African Border War
Production history
Designed	1944
Produced	1955
Specifications
Weight	5,620 kg (12,390 lbs)
Length	9.875 m (30 ft)
Barrel length	6.45 m (21 ft 2 in)
Width	2.35 m (7 ft 9 in)
Crew	7~9
Caliber	122 mm (4.8 in)
Breech	Horizontal sliding wedge
Carriage	same as D-20 152 mm gun howitzer
Elevation	+45/-5 degree
Traverse	45 degree
Rate of fire	Maximum: 8-10 rpm
Muzzle velocity	885 m/s (2,907 ft/s)
Effective firing range	Indirect: 23.9km (15 mi) Direct: 1,080 m (1,181 yds)
Maximum firing range	24 km (15 mi)

The 122mm D-74 towed gun is a Soviet built gun. Developed in the late 1950s it provided direct and indirect fire for the Soviet Army. Today it is in reserve units with the Russian Army.

It is in active service with the Sri Lankan Army, the Egyptian Army and the Pakistani Army.

The 122 mm (originally 48 lines) calibre has been in Russian service since the early 20th century. After World War II the Soviet Union developed two new long range guns to replace existing 122 mm and 152 mm guns such as 122 mm gun M1931/37 (A-19), 122 mm gun Model 1931, 152 mm gun Model 1910/30 and 152 mm gun Model 1935 (BR-2). The two new guns were the 122 mm D-74 and the 130 mm M-46.

The D-74 design was probably initiated in the late 1940s and it was first seen in public in 1955. It was designed by the well established design bureau at Artillery Plant No. 9 in Sverdlovsk (now Motovilikha Plants in Yekaterinburg), led by the eminent artillery designer Fëdor Fëdorovich Petrov who was also responsible for several World War II and later artillery designs. The design team also developed the 152 mm gun howitzer D-20 at much the same time, and both D-74 and D-20 use the same carriage.

Both the 122 mm D-74 and 130 mm M-46 entered Soviet service, but the heavier shell and greater range of the M-46 meant that it outlasted the D-74.

The D-74 has a 52 calibre barrel, with a double baffle muzzle brake and a semi-automatic vertical sliding block breach, with a tied jaw and the block moving down to open. The barrel is mounted in a long ring cradle with the trunnions just forward of the breach. The recoil system (buffer and recuperator) is mounted on the cradle above the barrel. Compression balancing gear is attached behind the saddle support, passing through the complex shaped saddle to connect to the cradle just forward of the trunnions. This can be manually re-pressured by a pump below the breach. The breach has a projectile retaining catch to prevent the shell sliding out at higher elevations before it is rammed with a manual rammer.

Top traverse totals 60° and the vertical elevation range in -5° to 50°.

Box girder section split trail legs are hinged to the cradle support, with bolts to lock them into either the open or closed position. The cradle support also has a bolt for locking the barrel in centre for traverse before towing the gun. There are small spades at the end of each trail leg, and fittings for large spades that are carried on the side of each trail leg. The large spades are used on soft ground and are fitted to the trail ends via have a pintle in the same way as the similar spades on M-46. These spades are the main difference from the D-20 carriage.