USSR Aircraft weapons

[CharlesBronson]

UBK.

The UBK was the less manufactured variant of the Berezin heavy MG, designed for non-synchronizated fixed emplacements found little use between the all-in-the-nose firing trough the propellers russian fighters.

UBK, wing emplacement in MiG-3.

In Aleksandr Pokryskhin Mig.

( profile from: "Soviet aces of WW2" Osprey aircraft of the aces series)

From February 20, 1941, a new version with two further 12,7 mm UBK guns on under-wing pods with 145 rounds each in the Mig-3

Also was mounted in the heavy fighter Pletyakov Pe-3 and some in the wings of Polikarpov I-16 type 18.

2 UBK, below nose of Pe-3.

The rate of fire was superior to both german MG-131 and US M2 Browning heavy Mgs.

 

[CharlesBronson]

12,7x108 mm for Universaly Berezina:

The design of this ammunition was strongly influenced by the german antitank Mauser cartrigde 13x92sr and the USA .50BMG (12,7x99mm) nevertheless it was designed to be more powerful than its predecessors.

Incidentally this ammunition was used also in some experimental antitank rifles, but in 1940 that task was taken by the bigger and meaner 14,5x114mm cartrigde.

B-30: Armor-piercing steel core, Projectile weight 51.9 grams, initial speed 810-825 M/s.

T-38: Ordinary ( ball) tracer (green), Projectile weight 43.5 grams, initial speed 840-860

B-32: Armor-piercing incendiary, weight 48.2 grams, initial speed 810-825 M/s.

BZT-44: Armor Piercing-incendiary-tracer with steel core, weight 43.7 grams, initial speed 840-860 M/S.

BZF-46: Armor-piercing incendiary of white phosphorus, weight 47.0 grams, initial speed 810-825 M/s.

MD-46: Explosive, weight 41.0 grams 840-860M/s: filled with 2,4 grams of penthrite.

There was also an "improved armor piercing" , but it seems that this ammunition was destined to the land based DShK heavy machine guns and no to the UB.

BZ-41 API: Armor-piercing, core of tugsten, weight 53.8 grams, initial speed 815 M/s.

Squematic cut 12,7 mm x 108 ammo, left to righ, AP-T, API, and two types HE, with and without fuze.

 

[HoHun]

Hi Charles,

>12,7x108 mm for Universaly Berezina:

Thanks for the data! Did you ever come across weight figures that give the mass of the entire cartridge, ideally even including the weight of the belting? I've collected this kind of data for a number of weapons in order to make an international comparison, but for the various Soviet weapons I've been unable to find anything useful so far ...

Regards,

Henning (HoHun)

 

[Glider]

CB Just a brief thanks I have always been impressed with Russian weapons and don't feel that they get the respect they should. Its good stuff.

 

[CharlesBronson]

You are welcome lads.

Thanks for the data! Did you ever come across weight figures that give the mass of the entire cartridge, ideally even including the weight of the belting?

The entire ammo weights 142-158 grams depending on the projectile type, sorry but I have no data of the belt.

12.7x108 - MUNICION.ORG

 

[CharlesBronson]

Shvak 20 mm.

The second attemp of Shpitalny Vladimirov to produce a "krupnokalibr" ( large caliber) variant of the Shkas was by far more sucessful.
The steps to follow were not very complicated since the new gun shared several pieces with the previous and failed 12,7 mm model.
The chambers was modified to accept a projectile of completely straight case and the corresponding rim.
ShVak 20 was fed by desintegrable metalic belt and revolving drum, it was operated by gases taken by a port amid barrel.

1st time of the cycle of feeding.

Finally the round in position, when the trigger is depressed the bolt will advance and introduce it in the chamber firing the cartrigde.

squematics from:

Ignition of the cartrigdes was percussion. An improvement introduced in this caliber was that small porcentanje of the gas taking was bleeding towards a a grooves in the chamber, this provide some " flotacion" to the used case taking off it of the walls easing the extraction thus increasing the gun reliability.

It was first tested in 1936 in a experimental variant on the Polikarpov I-16 designated I-16P (P = Puschka = cannon)

The Shvak was accepted for service in 1938 in good condition and his first actions battle took place in 1939 against Japanese aviation in the border dispute of Mongolia. It proved to be very effective against the agile but slightly constructed Ki-27 JAAF Fighters.

 

[CharlesBronson]

Sticky topic, nice

ShVak 20 mm (II)

The Shvak also was adapted for the use in armored vehicles, the TNSh weapon (Tankovy Nudelman Shpitalny) that it was used in the light tank T-60 . It was basically a fixed ShVak in armored turret emplacement.

About 34601 were manufactured in 1942, in 1943 some 26499, 25633 in 1944 and 13450 in 1945, the production stop with a series of 750 units manufactured in 1946. This gun use in several types of fighter , I-16, yak-1, Yak-3, Yak-9. Lagg-3, La- 5, La-7, etc.

Also a pair was put into some Hurricanes of " Lend and lease". As defensive armament settled in the Tupolev Tu-2, Petlyakov Pe-8 and the Yermolayev Ye-2.

Characteristics:

Caliber: 20x 99R

Cycle of operation: Gas operated, sliding bolt.

Length overall: Wing mounted 1679mm, variant for turret 1726 mm, Engine 2120 mm.

Rate of fire: 740-760 per minute (wing and turret) 610-615 dpm, synchronous variant.

Weight: 40 kg (wing) 42 kg (turret) 44.5 kg (engine)


Shvak in experimental fighter I-180.

Polikarpov I-16 Type 24.

Underbelly pod in Pe-2Sh, note duct curved below the gun wich is the spent case chute.

 

[CharlesBronson]

2 more images; engine installatioon of the ShVak between the "V" of V-12 Klimov engine ( copy of Hispano Suiza Y-12), note the emergency charge wire handle in the aft position.

Needless to say: to manually charge this weapon required a lot of effort by the pilot.

 

[CharlesBronson]

20 x 99 R ammo for ShVak:

The cartrigde case design for this weapon is somewhat archaic, it looks like a oversized revolver ammunition.

James N Chinn is his study stated it was derivated from an ancient 25mm Gatling manually operated machinegun round. However the most likely is its was developed straightening the bottlenecked 12,7 Shvak case.

The muzzle velocity is slightly bigger than the Mauser MG 151/20 but the german gun could fire heavier projectiles.

OZ: Incendiary-explosive, weight projectile 96 grams, initial speed 770m/s

OZT: similar to the previous one but with tracer.

OF: explosive of fragmentation, weight projectile 91 grams, V0 785 m/s

OFZ: Explosive of fragmentation with incendiary element.

BZ: armor-piercing, steel hardened core with 2.5 grams of component arsonist in the end, weight 96 grams, V0 750 meters by seg. Penetration 24 mm at 100 meters normal plate.

BZT: similar to the previous one but with tracer in the base.


Feeding the TNSh in T-60 tank.

20 x 99mm belt for Il-2 sturmovik.

According to russian sources the TNsh tank gun could also fire a tugsten carbide core ammunition, that could penetrate the side armor in Panzer III IV up to 350 meters.

 

[Tony Williams]

You are right that the 20x99R was developed from the 12.7x107R ShVAK ammo - I have examples of both in my collection.

 

[CharlesBronson]

Yup, that was the more logic path to development, but I think Chinn want to undestimate a little the cartrigde, and indeed is not a very creative design but the result of a simple adaptation.

Thanks for the confirmation.

Taubin MP-6

At the end of 1939 the VVS High Command was already thinking about a caliber weapon superior to the ShVak. In January of 1940 the task to design the design the new 23 mm gun was given to to technical office OBK-16 lead by Y. Taubin and M. Baburin .

The gun was long recoil operated and was feed by a complex magazine of 60rounds wich combined 10 clips of 6 cartrigdes.

As result given the long and intermitent mechanical movement added to the long travel of the bolt in each firing the MP-6 had low rate of fire, about 300 dpm. Soviet Air Force was not satisfied with this figure so the VVS ordered the OKb-16 to increase the rate of fire.

The russian technicians adapted an "accelerator", mechanical device wich increased the velocity of the bolt thus increasing the rate of fire. With this modification the MP-6 could reach 500 rounds per minute.

The first prototypes of the MP-6 were tested in imported Me-110 from Germany (two cannons in the nose) and in the Mig-1 prototipe, (between the V of the Mikulin engine)

The Mp-6 also was placed in a pairs in the wing of a single place Il-2 and tested in conjunction with the later Volkov-Yartsev of equal caliber, the results were conclusive, the production of the MP-6 I conclude in April of 1941 with less than 100 examples constructed… the VYa was completely superior.

 

[CharlesBronson]

Taubin PTB-23.

This was a variant designed for improve the armament of the T-60 and T-70 light tank, the designation goes for Protivotankoboe Taubin Barubin, antitank of Taubin and Barubin.

The gun was fully automatic and used the lower 300 rpm rate of fire. It was loaded by 9 shots clips introduce manually by the gunner.

Again the PTB-23 was not a suitable design, the clip was usually caught by the ejector and the yun jammed a lot.

In those stalinist times failure was a costly option and certainly that is the case in this weapon, Taubin and Barubin were arrested and later shot by the NKVD

 

[CharlesBronson]

Taubin 37 mm, a mistery:

The only mention of this gun appeared in the book "Soviet X- Planes" by Gunston/Yefim Gordon.

According to that a Taubin 37 mm with 81 rounds was put into the Gudkov Gu-1 a design based in the P-39 airacobra. The emplacement was in the nose like the way the P-39 had its Colt M4 gun.

For several reason I think this is a mistake and probably Gordon mixed up with the 23 mm variant.

For example:

A) I dont think you can put 81 rounds of 37 mm catrigdes in the fuselage of a fighter, as comparative the P-39 have 32 and that round had a smaller size than the russian ammunition.

B) Executed Taubin and liquidated his design team is very unlikely that he had time to develop a 37 variant of his failed gun.

C) If something is valued in russian armaments is reliability, I dont believe the VVs would continue to use a weapon that has proven unreliable already.

Whatever be the case the fact is the Gu-1 didnt survive too much, the first and only prototipe crashed in his first flight in June 1942, killing the Pilot P. Nikishin.

 

[CharlesBronson]

Volkov Yartsev VYa-23

June 22th, 1941, 4:30 am, the most efficient Army in the World attacked Soviet Russia. Wave after wave of german armored vehicles penetrated the border defenses and knifed deeply in the Russian motherland.

Despite some local victories by T-34s and KV-1 the nazi advance seems unstoppable.
The VV-S quickly realized that the Shvak 20 mm gun was only adecuate to fend off light armored tanks and halftracks like the Pz II or Sd.Kfz 250. However the 20mm bullet did not penetrate the main tanks Panzer III and IV except by chance.

Given the failure of the Taubin guns they had not an adecuate anti-armor airborne gun. The VYa-23 wich was in development shortly before the german onslaught was quickly put in service.

The design began in june 1940 after the armament branch of the VV-S asigned TSKB-14 ( office for armament design 14) F.N Volkov and Boris Yartsev the task to adaptation the basic Berezin UB heavy MG mechanish to the new 23 mm round just developed for the Taubin MP-6 gun.

F.N Volkov.

In april 1941 the prototipes of both design were tested in attack and fighter aircrafts, the Volkov-Yartsev was by far more reliable thus entering in large scale production in June 1941. Two weapons were experimentally put into a Lagg-3 but the VVS devoted almost the entire production to the IL-2M and IL-2M3 attack aircrafts.

IL-2M installation.

The normal supply was 200 rounds, reduced to 150 rounds in the single place heavy fighter Il-2I.

The VYa-23 was gas operated, desintegrable belt feed and pneumatically charged. The rate of fire was variable adjusting the gas passage between 540 to 700 rpm. Usually the cannon was set in 560-570 rpm to ensure reliability.

More than 64500 examples were manufactured between 1942 and 1947 in the State factories Nº 6 and Nº 66.

VYa-23 characteristics.

Caliber: 23x152 belted.

Rate of fire: no less than 540 rpm.

Overall Lenght: 2147 mm

Barrel lenght: 1640 mm

Grooves: 10 right twist.

Muzzle velocity: 880 to 910 m/s.

Width: 160 mm

Height: 193 mm

Weight unloaded: 66 kilos.

 

[CharlesBronson]

A well known photo of Il-2m, in this we can aprecciate the huge muzzle blast in the VYa-23.

Double VYa emplacement, used in the prototype of attack aircraft Tomashevich Pegasus.

 

[CharlesBronson]

23x152 ammunition.

Two types manufactured, a few without belt for the Taubin guns and the belted variant for the VYa-23.
3 projectiles manufactured, exercise, armor piercing and high explosive.
The AP shell weights 210 grams and the HE 196 grams. Muzzle velocity 885and 900 meters per sec, wich allowed a very flat vbullet trajectory. The tracer element in HE bullet glow until 1500 meters.

The BZ ( antiarmor) projectile could penetrate 40 mm rolled homogeneous armor at 300 meters, meaning it could go trough the side armor of german medium and light tanks easily.

Penetration of VYa-23 in side turret Pz 38 t ausf E ( 20 mm armor)

 

[CharlesBronson]

Shpitalny Sh-37

While perfecting the ShVaK the designed Boris Shpitalny worked also in a 37 mm gun with the collaboration of the OBK-15 bureau.

The large caliber weapon was a response to a requeriment of the army for a weapon capable to destroy the main tanks of the of the enemy ( the other more lightly armed aircraft like the Polikarpov Ivanov and Ilyushin Il-2 would deal with the infantry, lorries and support vehicles)

That a requeriment sighseeingt the need of a heavy caliber airborne weapon was proposed in a date as early as 1936 is a real achievement for the soviets.

The Sh-37 is 3,7 meters long and weights 315 kg, is a gas operated with sliding breech automatic cannon.

The first Sh-37 was ready in 1938 emplaced in the heavy attack Polikarpovs VIT-1 (Vozdushnyj Istrebitel Tankov = frontline antitank fighter) and VIT-2. Two cannons were installed in the wingroots of the VIT-1 feeded by a non linked 60 round magazine.

Polikarpov VIT-1

The 1940 VIT-2 have a single Sh-37 in a underbelly pod feed by a 70 round magazine.

The accuracy of those shooting at ground targets is recorded as very good, however both aircrafts were overloaded and had bad handling characteristics ( the VIT-1 was recorded as dangerous when a sh-37 jammed and the other fire giving a notable yaw)
None managed to enter in service.

 

[CharlesBronson]

Shpitalny ShFK-37.

A redesign of the Sh-37 with shorter barrel and modified to save weight.
In that way the mass was reduced to 302 and the lenght to 3,1 m. The new weapons was designed SFK-37.

At the end of december 1942 the VV-s high command decide to munt a pair of the heavy caliber Shpitalny SH-37 guns in the IL-2 for combat test against armor.

The ninth Il-2 with the guns SHFK-E ( Shpitalny large caliber gun, wing mounting) arrived in the regiment only of on 18 January, 1943, and in the troop tests the participation did not assume. Attack aircraft Il-2 with the guns SHFK-E participated in the war with the air regiment wbetween 27th december 1942 to 23th january 1943 in the outskirts of Stalingrad and took part in the defeat of the 6th german army.

Task for manufacturing this aircraft Of s.V.Ilyushin obtained in march 1941, however, in connection with the strong overloading OF OKB by works on the series Il-2 AM-38 the defects of gun SHFK-E", which were appeared in the course of operation, Il-2, armed by such guns, it was built with plant № 18 only toward the end of June 1941, and all necessary flight tests of attack aircraft were carry out 8 July.

The large overall dimensions of guns SHFK-E and magazine feeding (magazine capacity of 40 projectiles) determined their arrangement in the fairings under the wing of aircraft Il-2. Because of the installation on the gun of its large store it was necessary to reinforce the lower structure of the wing which not only complicated the construction of fastening gun to the wing (gun it were fastened to the shock absorber and with the shooting it were moved together with the store),

Also it required to make for it fairings bulky with the large cross section. Gun SHFK-E, including store for the cartridges as its component part, in the wing version had 387 components. The weight installation of this 37 mm cannon on the aircraft was 302,5 kg. Besides the guns and the machine guns, into the composition of the armament of attack aircraft entered 8 rocket RS -82 or 200 kg of bombs.

State conducted tests showed that flight-performance data Il-2 with the 37 mm cannons SHFK-E", in comparison with the usual series one-place Il-2 with the guns SHVAK or Vya, were noticeably reduced. The stormovik became more "inert" and more complex in the to maneouver, especially on the turns and the turns at the low altitude. The agility deteriorated at the high speeds. Pilots complained about the significant loads on the controls when turning or yawing.

Nevertheless, the flight-test results of new attack aircraft were acknowledged as a whole satisfactory. With the normal gross weight of 5864 kg the maximum speed in the earth did not exceed 373 km/h, at the height 2400 m of 409 km/h.
It take 2. 12 min to reach 1000 meters height and 5,36 minutes to 2500 m .[/

The landing speed was slightly increased 146 km/h. Take off 515m, path on the landing 535 m.
Highest velocity in a step dive: 590 km/h . maximum 728 km. Rate of fire SHFK-E according to the data of range tests average was equal to 169 shots per minute with the initial velocity of projectile approximately 894 m/s.

 

[CharlesBronson]

SFK-37 in LaGG-3

In August 1941, three LaGG-3s produced by GAZ-23 in Leningrad were retrofitted with a Boris Shpitalnyy's 37 mm Sh-37 gun with 20 rounds. This weapon was firing through the cylinder banks and the propeller's hub; its barrel protruded from the spinner for about 60% of the spinner length.
The muzzle of the SZF-37 was provided with perforations to act as muzzle brake ( in the same way as the guns used in Il-2m)

This aircrafts were named K-37 ( LaGG-3It or LaGG-3 -37 according other sources and immediately sent to the front.
The gross weight of the plane was increased to 3363 kg, and its speed decreased of 5-7 km/h ; the climb rate and ceiling were lower than the standard LaGG-3s of the same series. The handling qualities were preserved due to the installation of automatic slats, as those installed on later versions.

Emplacement between the "V" of the Klimov engine. Note the 22 rounds "horsecollar" magazine.

Tests demonstrated that the plane was a stable platform of fire, and the gun had a good kill probability against targets at a range of 300-400 m; the gun was intended both for use against enemy bombers and ground targets.
20 LaGG-3s K-37 were built in late 1941, and they were delivered to 42 IAP on the Bryansk front in early 1942. The first combats were successful, and three enemy bombers were destroyed.

However, it was noted that 20 rounds for the gun were an insufficient supply. The pilots had to fire only after having aimed carefully, and only in short burst of 1-2 rounds, both to save ammo and because the recoil forces caused the plane to drop on its nose and to lose the alignment with the target, particularly if the fighter was flying at low speed. Incendiary-explosive shells were used against flying targets, while armor-piercing shells could be used against ground armored targets.

Number "90" was one of the original 20 evaluation machines mounting the Sh-37 gun. It appeared to have survived with the 42 IAP until the winter months of 1942-43.

In September-October 1942, these planes were utilized during the Battle of Stalingrad by the 291 IAP with good success, shooting down 13 enemy bombers; 7 K-37 were lost in combat on that occasion. During their use, they were escorted by Yak fighters. A.Ootin, commander of the 220 Fighter Air Division (IAD) to which the 291 IAP was assigned, was very satisfied with these planes, and wrote that one or two hits in any part of an enemy plane were sufficient to shot it down.

 

[CharlesBronson]

By the way the source of color profile is here:

Modeling the VVS: Big Gun Fighters, Part 2