20/3 mm M55

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20/3 mm M55


M55 A4 B1 of the former Vojska Republike Srpske

General Information
Military designation: 20/3 mm M55
Manufacturer country: Serbia
Model variants: M55 A2, M55 A3 B1, M55 A4 B1, BOV-3
Weapon Category: Anti-aircraft gun
Team: 6 men (optimal)
Technical specifications
Overall length: 4.30 m (driving condition)
Pipe length: 1,956 mm
Caliber :

20 mm

Caliber length : L / 70
Cadence : 700 rounds / min
Elevation range: + 83 ° to -5 degrees
Side straightening area: 360
Furnishing
Ammunition supply: Drum magazines with 60 rounds each

The M55 is a Yugoslav three-barreled anti - aircraft gun in 20 mm caliber. The weapon was developed from 1955 and used extensively during the Yugoslav Wars. Some modifications have been made to the weapon since its development. In addition to the basic model M55 A2, the variants M55 A3 B1, M55 A4 B1 and BOV-3 were created.

The development and series production took place at the weapons manufacturer Zastava in Serbia .

Basic model M55 A2

The cannon is a licensed construction, consisting of three 1,956 mm long barrels of the Hispano-Suiza HSS-804 20 mm L / 70, which is mounted on the HSS 630-3 undercarriage. When driving, the length is 4.30 m, the width 1.27 m and the height 1.47 m. To enable easier reloading, the middle barrel is offset horizontally to the rear. The ammunition is fed for each run by means of a drum magazine, in which 60 rounds can be loaded. The cannon is set up for use on three foldable feet and the wheels are folded up, but the wheels can also be fired in an emergency. The chassis is sprung and folded up hydraulically. The cannon can reach a top speed of 80 km / h, and the towing vehicle is TAM-110 4 × 4 trucks. The total weight including ammunition is 1,100 kg, without ammunition 970 kg.

The shooter sits at the rear end of the cannon and adjusts the side (360 °) and height (+ 83 ° to −5 °) with two handwheels. It is fired with a pedal. An automatic optical-mechanical sight (PANS-20/3) is available to the shooter for target acquisition. The shooter receives various data when capturing and forwarding the target; this means it is not necessary to hold up when firing. With this optics, however, only aircraft in the subsonic range can be fought. Targets with speeds of around 1,000 km / h can be fought at a distance of 1,500 m and slower targets up to a distance of 2,000 m. The maximum range against air targets is 4,000 m. A theoretical rate of 700 rounds per minute is possible per barrel; all three tubes could fire 2,100 rounds per minute, but this cannot be achieved in practice due to the reload times.

In addition, the cannon was used extensively against ground targets in ground combat. The firing range against ground targets is 2,500 m, the maximum firing range is 5,500 m.

M55 A3 B1

The difference to the basic model is the hydraulic directional drive of the gun, which is driven by a small rotary motor with 8 HP and 160 cm³ on the right side of the gunner. This system enables faster straightening and is operated using a joystick . The total weight increases to 1,235.5 kg with ammunition and 1,150 kg without ammunition. However, the tubes, the landing gear and the aiming device are identical to the basic model.

M55 A4 B1

BOV-3

A new computer-controlled sighting system was installed on the A4 B1, which automatically notifies the gun when the target is caught. Furthermore, the Wankel engine was mounted under the shooter, since the side version caused vibrations on the three tubes due to the weight distribution. When the cannon is brought into position, the landing gear is removed, and a small anti-splinter shield was installed in front of the sighting device and the shooter.

BOV-3

The BOV-3 anti-aircraft system is an A4 B1 that was installed in a BOV armored transport vehicle .

ammunition

  • 20 × 110 mm tank incendiary grenade cartridge M60 (with and without tracer device ): deep black paint with a strawberry-red ring in the upper third of the grenade. The shell of the garnet is made of hardened steel and in the rear part holds the phosphorus fire filling, which ignites when it hits a target.
  • 20 × 110 mm explosive fire grenade cartridge TZO M57 (with and without tracer device): Chrome-yellow paint with a strawberry-red ring in the upper third of the grenade and a green ring above the guide ring. The garnet shell is made of steel and has a Trotyl explosive filling inside with a fire filling in the middle, which ignites when a target is hit. The sensitive AZZ UT M57 head detonator screwed onto the grenade is a powerful percussion detonator with a self-destruct device that starts after 4.5 to 9.5 seconds.
  • 20 × 110 mm M79 training bullet cartridge (with tracer): Dark green paint with a light green ring above the guide ring. Bullet casing made of steel with an impact fuse, which ignites a lightning filling when it hits a target in order to enable a better observation of the hit pattern.
  • 20 × 110 mm M77 training bullet cartridge: Creamy white. Plastic bullet filled with iron powder and provided with predetermined breaking points, which bursts open after leaving the pipe.

Web links

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