30mm Gryazev-Shipunov GSh-30-2
AO-17A
Overview
30mm GSh-30-2
Forward view of GSh-30-2 twin barrel autocannon.
Source: en.topwar.ru -
© Copyright lies with original owner
1978 (state tests)
Russia - ZiD
TKB-645 (factory index)
ГШ-30-2 (Cyrillic)
9-A-623 (GRAU index)
GSh-302 / GSh-2-30
Description
Introduction
The GSh-30-2 is a late Cold War era autocannon of Soviet origin. It was developed as part of a program to unify all aviation, army and naval autocannon to the 30x165mm caliber.
Design
As an upscaled version of the GSh-23 the GSh-30-2 was nearly identical. These autocannon function using the Gast principle. In this twin barrel setup the recoil from one barrel cycles the action of the other, allowing for an instant high rate of fire. A single belt feed both barrels. A small change on prototype versions was a flame ignition for dud rounds instead of a single gas charge per barrel. Theoretically allowing a jammed gun to be cleared more than once, but this mechanism proved unreliable and was omitted from production models.
Firepower
Compared to the GSh-23 the rate of fire was only slightly lower at 3.000 rpm. The increased mass and velocity of the rounds fired make the GSh-30-2 a factor 2.2 times more combat effective than the GSh-23 according to Soviet state tests. Then entire 250 round belt allows for 5 seconds of fire. The muzzle velocity is over 900 m/s, depending on the type of ammunition.
Platforms
The GSh-30-2 is used to arm two of the premier close air support assets of the Soviet Union: the Su-25 ground attack aircraft and Mi-24P attack helicopter. These have 250 and 260 rounds to fire respectively. There is no gun pod for the GSh-30-2 possibly due to the recoil being unmanageable for standard aircraft suspension lugs.
Variants
GSh-30-2
Original model designed for fixed wing aircraft use. The barrels are air cooled by the airflow. Most were upgraded to, or produced as, GSh-30-2V standard with a muzzle device that vents the gasses from the muzzle downward. This reduces the chances for a compressor stall in the engines of the Su-25. Even though the muzzle velocity of the GSh-30-2 is lower than that of the GSh-30-2K the armor penetration is about 20% higher due to the airspeed of the aircraft.
GSh-30-2K
Variant with modifications for helicopter use. This model has longer barrels to increase the muzzle velocity and extend the barrels in front of the cockpit to divert the blast. Water cooling jackets are added since the airflow does not provide enough cooling. Additionally there is a low rate of fire setting of about 300 rpm.
Details
Media
30mm GSh-30-2V
Close-up of the muzzle device of the GSh-30-2V as used on the Su-25 ground attack aircraft.
Source: www.airwar.ru
Copyright: Copyright lies with original owner
30mm GSh-30-2K
A view of the long barrel GSh-30-2K and its single ammunition belt as used on the Mi-24P attack helicopter.
Source: www.airwar.ru
Copyright: Copyright lies with original owner
30mm GSh-30-2K
Mi-24P seen firing its powerful 30mm GSh-30-2K autocannon in flight.
Source: www.airwar.ru
Copyright: Copyright lies with original owner
Application
Mil Mi-24P
The Mi-24P is armed with a GSh-30-2 on the right hand side of the cabin. Unlike the Yak-B the GSh-30-2 is fixed, requiring the nose of the helicopter to be pointed on target. Since the gun is off center firing it results in a yaw towards the right, especially with the rate of fire set to high.
Sukhoi Su-25
The Su-25 is armed with a single GSh-30-2 mounted below the cockpit, offset slightly to the left in a VPU-17A mount. A total of 250 rounds are carried.
On the Su-25T variant the gun was relocated to a central position in an NSTU-17 mount with reduced 200 round ammunition capacity.
Related articles
23mm Gryazev-Shipunov GSh-23
The GSh-30-2 follows the same design as the GSh-23, but is upscaled to the 30x165mm cartridge.
30mm Gryazev-Shipunov GSh-301
The GSh-30-2 designation is very similar to the GSh-301, which is a very different type weapon, being a single barrel revolver cannon.
30mm Gryazev-Shipunov GSh-6-30
The GSh-30-2 was also developed as a lighter, more compact and more manageable alternative to the six barrel GSh-6-30, which can fire faster but otherwise proved less suitable for aviation use.