20mm ShVAK aircraft cannon, sub-caliber device
| This cailber was created by
necking up the 12,7x108R case of the 12,7mm ShVAK to 20mm. The idea was
to create a new weapon by only changing the barrel.
The 20mm ShVAK cannon was introduced into service in 1936 as armament for aircraft. The Shpitalny-Vladimirnov Aviatcionnaya Krupnokalibernaya cannon was gas-operated and 1760mm or 2210mm long. Its rate of fire was 800rpm, with its weight of42kg or 56kg. The ShVAK cannon had certain similarities to the Hispano-Suiza cannon HS 404, with its 1245mm or 1700mm long barrel, latter was intended to be installed in the engine vee, firing through the propeller hub. In 1945, the improved Berezin design B-20 aircraft cannon in this caliber was introduced, which had
the same rate of fire, but it weighed only 25kg and was much more reliable. The gas operated cannon could be mounted in wings and turrets. After WWII, it was mounted as PV-20 defensive cannon in turrets of heavy bombers.
In the ground role two slightly modified versions of the ShVAK cannon were used on light tanks like the T-30 and T-60, they were called TNSh–1 and TNSh–20.
The cartridges have brass cases and a percussion primer. They are filled with 18,1g of tubed propellant 0,7x2. Shells have copper driving bands. HE shells are either fuzed with the K-6, A-20 or MG-3 nose fuze. The K-6 uses a setback force safety, while the A-20 uses a coiled band safety device. However, the A-20 is also found with a different safety device. Projectiles are blackened (blued) against corrosion, HE shells have red fuze tips, API shells black tips with red rings below. HEI-T shells have an additional green band above the driving band. However, colour marks were not consistently the practise. Cartridges are linked in desintegrating steel belts in 120 and 180 rounds quantities.
Ammunition for the sub caliber devices are maufactured in Russia and the Czech Republic.
Ammunition used during WWII:
|A Czech post WWII AP-T round is
known, which uses a pointed solid steel shot with tracer. This is
exactly the same type as used in the 20x138B cartridge and is shown in
the second picture of the
20x138B section (the one with the red powder bag). Contrary to the
shown, the projectile for the 20x99R is originally unpainted, cases are
brass with the headstamp IOU and a date from the early 50s.
The performance in the post WWII sub-caliber devices, used in RFAS tanks and artillery guns, is not known.
|23x115 23mm NR/NS and GSh aircraft cannons|
|The 23mm Nudelman-Suranov aircraft cannon NS-23 was
1945 to replace the VYa cannon; actually it was a NS-37 cannon scaled
The recoil operated weapon weighted 37kg and fired 550rpm, it was
encountered in 3 different versions: In wing or fuselage mounts on
fighters like the MiG-9 and the MiG-15, in synchronised mounts NS-23S
on propellor driven aircraft like Il-10, La-7 or La-9 and as bomber
defence turret cannon.
The Nudelman-Richter NR-23 became available in 1949 and was based on the VYa cannon. Compared to the NS-23, the NR-23 was gas operated and weighted 39kg but fired an improved 850rpm. It became the major barrel weapon of the Russian jet figters like the MiG-17 and replaced the B-20 as bomber defence cannon.
China copied the NR-23 and introduced it as "Type 23-1" cannon.
The original old rounds used a lower power charge of
33g of sw 4/7 powder and achieved only 690m/s at a maximum pressure of
The ammunition used in the NR-23 and NS-23:
|Inert drill rounds were used as well.|
|Czech NR/NS rounds from left to right: Three different drill rounds; the "s" for "skolni" is Czech and means "drill round". HEI-T round, HEI-T round with decoppering lead-piece and API round.|
|The 1954 introduced AM-23 is a single barrel gun and
weights 43kg. It is gas operated and belt fed and fires 1250rpm; its
overall length is 2170mm.
The gun was developed by Afanasev and Makarov and was used as a bomber
cannon. With it, the improved ammunition was introduced, featuring
improoved projectile design and better ballistic properties.
The 1965 introduced GSh-23 and GSh-23L double barrel guns (MiG 23 & 27 + bomber defence tail mounts), operating with the Germany-invented "Gast" principle, fires 3000-3400rpm and mixed ammo belts always consist of two rounds of the same kind next to each other. The GSh-23 weights 50kg and measures 1387x165x168mm, the GSh-23L is slightly modified and weights 51kg and measures 1537x165x168mm. The "L" means "Localizator" and describes a gas port at the barrels that allows the powder gases to be used to soften and reduce the recoil force. The first time the GSh-23L appeared in the GP-9 gun pod with 200 rounds of ammunition below the fuselage of the MiG-21.
The SPPU-22 gun pod houses a flexible mounted GSh-23 cannon that can be traversed up to 30° downwards.
The pod can hold up to 260 rounds and weights 320kg fully loaded, it is used on external stations on the Su-17 and MiG-27.
Another gun pod, designated UPK-23-250 houses a GSh-23 cannon with 250 rounds and is used on the MiG-23 and combat helicopters. The cannon is not flexible and overall weight of the loaded pod is 218kg.
The six-barrel rotary cannon GSh-6-23, Russian designation 9-A-768, has an impressive rate of 9000 to 10000rpm. Compared to the western 20mm "Vulcan" cannon, the GSh-6-23 weights only 76kg, has nearly twice the firing rate and does not require an external power sorce. It is 1400mm long and can either be fed with a linked cartridge belt or a linkless feed system.
The SPPU-6 gun pod houses a flexible mounted GSh-6-23 cannon that can be traversed 45° downwards, to the left and the right. The pod holds 500 rounds and weights 525kg fully loaded, it is used on the Su-24.
The newer rounds for the modern automatic guns have an
improved powder charge to achieve 720m/s (depending on gun). A white
band is painted on the shell to indicate not to mix them up with older
rounds. Rounds use thicker walled brass cases with a KV-28 percussion
primer and have a propellant charge of 35-38g of improoved 4/7 Tsgr
The ammunition used in the AM-23 and GSh-23:
|Drill rounds exist as well of course.
|From left to right: TP or drill round, TP airburst round, HEI round, HEI round with decoppering lead-wire, PRL Chaff round with decoppering lead-wire, API round, HEI round, TP-Balloon round, HE-Balloon round.|
|23x152B 23mm VYa, ZSU AAA and sub-caliber device|
|This cartridge was introduced in 1941 designed for
the VYa Volkov
and Yartsev aircraft cannon.
The rate of fire was 600rpm and it weighted 68,5kg. It was 2140mm long; the basic idea was to create a suitable cannon to deal with German tanks. This aircraft cannon was gas operated and belt fed, two cannons were fitted in the Il-2 Stormovik ground attack airctaft in WWII. The VYa was extremely powerful for its time, and the AP shell could penetrate 25mm of steel plate at 400m.
Cartridges for the obsolete VYa slightly differ in dimensions and the primer used, and cases are brass. 30 cartridges are packaged in an airtight Zinc can, and 3 of those were packed in a wooden box.
The following ammunition was used in the VYa:
|Inert drill rounds may have been used as well.|
|From left to right:
OZT cartridge, OZT projectile, BZ cartridge with steel
windshield cap crimped to the projectile.
|Long after the war, the Soviet Union selected a
version of the VYa aircraft cannon to act as anti aircraft gun.
Compared to western 20mm AA guns, the slightly modified 23mm cartridge was far more harder hitting and had a considerably greater range than for example the U.S. Vulcan AA system.
A single 23mm ZU gun weights 75kg and is 2550mm long with a 2000mm long barrel, the rate of fire of this gas operated cannon is 1000rpm.
The ZSU-23-2 AAA is a towed double barrel, ground mounted gun weighting 950kg introduced in the early 1960s. Its bigger brother, the ZSU-23-4 Shilka, is a self propelled, radar guided, 4-barrel gun that is extremely effective on low flying aircraft. It fired 4x1000rpm and is fed by 50 round ammunition belts, stored in boxes. This round is the most widely used small AAA caliber of the Russian Federation and its associated states and was also often used against ground targtes.
The steel lacquered cases use the KV No.3 percussion
primer and use about 70g of 5/7 UFL smokeless powder, and some have a
piece of lead
wire as a decoppering agent with the charge.
The following ammunition is used in the ZSU AAA guns:
Drill rounds are used as well as blank rounds, the latter have a green painted cardboard cap, crimped in place and use VTX Powder.
|From left to right: Two blank rounds, TP-T round, TP-T with decoppering lead-wire, HEI-T with MG-25 fuze, HEI-T with B-19-Y fuze, TP-T round, API-T round, API-T round with decoppering lead-wire|
|The VS subcaliber device also uses this caliber in
the inserting barrel for the T54/55 tank gun. Only one projectile is
used, it looks like a blackened BZT shell, but the projectile body has
a blunt nose under the windshield cap. Cartridges for the VS subcaliber
can easily be identified by their brass cases, omitted colored marks
and their headstamp: 606 (manufacturer at 12 o´clock) BC-85
(VS - year of manufacture).
Ballistic performance in the subcaliber device is not known.
|23x260 Rikhter R-23 aircraft cannon|
|This unconventional type of ammunition came up
arround 1957 at the Ordnance Design Bureau OKB-16 of A. Rikhter, who
designed the 261P aircraft cannon. This new 23mm cannon introduced as
R-23 is shorter than any other cannon in a comparable caliber; it
weighs 58kg and is able to fire 2500 rounds per minute.
Contrary to Western high performance automatic
cannons, that use multiple barrels and an external power source
(Gartling type guns), the
Rikhter cannon operates only by the power produced from its ammunition.
The gun uses a single barrel and a revolving cylinder with four
chambers. These chambers are loaded from the front and underside of the
Cases have no extractor groove and are ejected by the gas pressure as
The advantage of this front loading system is, that the cannon could be
built shorter and the feeding mechanism is closer to the
center of gravity, which makes the gun ideal for turret gun
The R-23 cannon was used as a tail cannon in the TU-22
high altitude reconnaissance bombers and the first time it was examined
was when one of these bombers of the Lybian air force was shot down
over the African nation of Chad in 1987 by a French AA battery. Also,
India is known to have taken Russian the TU-22 into service and some
R23 cartridges were found by the
Israely armed forces who discoverd those in an erronous shipement of
AAA cartridges in Lebanon. Although many other calibers of the Rikhter
are known, no other weapons other than the 23mm 261P have yet to be
by western engineers.
The cartridges consist of a galvanized steel tube with a solid and conical base that holds the primer. The projectile is entirely contained in this case and fixed with a heavy crimp. The cartridge case is filled with single base nitrocellulose propellant. The 23mm R-23 cartridge shown below uses a conventional 23mm HEI projectile and an electrical primer-screw. A piece of lead wire is fixed to the base of the projectile with red tape. The designation "R-23" means "Rikhter 23mm" and designates the caliber of the projectile, not the outer diameter of the cartridge case.
A standard HEI projectile as for the 23x115 NS-23 is used, muzzle velocity is 850m/s, the overall length of the R-23 cartridge is 260mm, its overall weight is 51,5g.
|25x218SR 25mm M1940 AAA|
was an adopted Swedish Bofors design, introduced about
1933, however, the Russian rounds are not interchangeable with the
rounds for the 25x205SR Bofors L/64 AAA gun.
The M1940 AAA was introduced in early WWII and was used until the 1950s in the Soviet Union and then distributed to various small African nations, it was also used in the Yugoslav army as M40 AAA gun.
The M1940 was recoil operated and weighted 125kg, it was 1800mm long and had a 1450mm long barrel, cartridges were fed in 6 round charger clips.
The cannon was mounted on a 4 wheel carriage weighting 1,07 tons and had certain similarities to the 37mm M1939 AA cannon. A two barreled version fixed on trucks was used as well, however no further details are known.
Cartridges are fixed and have brass cases, and the
is 92g of 5/7 GR powder with a supplement charge of 2g 3/45 P powder.
Cartridges are percussion primed with a KV-2 or the Yugoslav M54P1
primer screw. Projectiles have three copper driving bands, with a
maximum chamber pressure of 2900kg/cm². The AP-T shell could
penetrate 28mm/60°/500m or 26mm/90°/1000m of RHA.
The following ammunition was used:
|Target practice rounds may be used as well.|
|25x218 25mm 110PM Naval AAA|
|This round is used in the Naval AAA guns M-110 and
110-PM in Russia and China, and it was an improved, postwar and rimless
version of the cartridges described above. The designation of the Naval
gun mountings are 2-M3, 2-M3M and 2-M8 for the Russian design and Type
61 for the Chinese gun.
These Naval mountings used two guns arranged one over the other, not side by side. The guns could be elevated -10/+83° and could be turnt 360° arround. The ceiling level for AA fire at maximum elevation was 1700m, its effective range 2300m.
These recoil operated guns were 2850mm long and had a 184mm long barrel that fired 225 rounds per minute each. Cartridges were normally fed by linked 65 round belts but could also be fed by 7 round charger clips.
The M-110 and 110-PM guns were mainly used on small ships and soon taken out of service in favour for the radar guided 30mm AK-230.
The brass cartridge cases are fitted with a V-016
percussion primer. They use 7 tubed 6/7 GR powder held in place by a
cardboard assembly and having a piece of lead wire as decoppering
agent. The older UOZR-85 round, taken with only minor changes at the
lower driving band from the earlier M1940
AAA gun, uses three copper driving bands, with the last driving band
inside the case. 34 cartridges are packed in a sealed No.10 or No.15
box, weighing 31kg, which have various descriptive letters painted on.
shells have only two driving bands, and the lower is still located
The following ammunition is used:
|Target practice and drill rounds may be used as well.|
|Legend: m= mass of projectile, om= mass of complete round, pm=mass of propellant, l= length of projectile, ol= overall length of complete round, Vo= muzzle velocity, cartridge case headstamps are given in the clockwise system, the clock-sections divided by "|" for better reading. The "|" does not mean an imprinted line in the headstamp. Example: symbol at 12 o´clock | 3 o´clock | 6 o´clock | 9 o´clock|