USSR Aircraft weapons, 1933-1950.

[Micdrow]

Originally Posted by wilbur1

Actually micdraw it is brass, it helps the bullet go done the bore alot easier without wearing it out. What made it armour peircing is inside. it would be lead wrapped around a smaller bullet made of tungsten or similar material

That makes sense Wilbur, thanks.

[Milos Sijacki]

Thanks for those photos and the info. I really liked it.

[CharlesBronson]

Interesting Charles, Any idea on what material the bullet was made out of to make it armor piercing? From the look of the picture it looks like the tip is brass.

Actually micdraw it is brass, it helps the bullet go done the bore alot easier without wearing it out. What made it armour peircing is inside. it would be lead wrapped around a smaller bullet made of tungsten or similar material

Indeed, it have a brass jacket with hardened steel core, a image worth thousand words.




If the bullet jacket would be made of steel it would destroy the barrel rifling in few shot, even fair is to say the germans ( who else ?) experimented with 9 and 7,92 mm very soft iron jackets for small arms ammunition in 1944-45 given the drastic lack of copper one of the component of brass.

Thanks for those photos and the info. I really liked it.

Nice, stay tuned, they will continue.

[Haztoys]

Great stuff ...CB

[CharlesBronson]

Preciated.

Berezin UB heavy MG 12,7mm.



In 1937 M. Y. Berezin began to project powerful 12,7 mm synchronous aircraft machine gun with the cartridge from 12,7 mm of infantry machine gun Degtyarev Shpagin DSHK 38.
During October/December of 1938 synchronous machine gun successfully underwent plant and range tests. On 12 April, 1939, there was some troop tests 12,7 mm machine gun BS (Berezin synchronous) by the decision of the committee of defense was neglected into the series production. 12,7 mm the machine gun Of berezina on the ring mount VUB-E in the assault aircraft IL-2.

The machinegun was gas operated with wedge locking system
The characteristic property of its device was the supply of ammunition belt not with the recoil of moving elements as in the overwhelming majority of machine guns, but with their counterrecoil, i.e. of the return spring of machine gun.

For the required reliability of belt feed return spring was made multiple-wire.

The merits of the Berezin machine gun included:

- Successful layout of entire automatism and separate mechanisms;

- High rate of fire

- Simple loading

- A comparatively small number of components and simple mechanism.

In spite of all its positive qualities, machine gun BS possessed some serious deficiencies. The difficulty of its recharging in air with the aid of the cable system, which required of the pilot of large physical efforts into the most decisive minutes of battle especially was shown; the defects, connected with the insufficient vitality of the separate parts of automation, appeared; they required the elimination of the reason for the appearance of some delays.

Working at further improvement of his system for purposes of the solution of these deficiencies and creation of general-purpose machine gun for its application at the basic weapon emplacements of all machine guns, M. ye. berezin developed general-purpose machine gun UB (universal Berezina) in three versions depending on site of installation - turret, wing and synchronous

UBT
UBK
UBS



Basic details and mechanisms of all three versions of machine gun were preserved, with exception of the trigger and percussion devices, into which were introduced some changes, connected with the specific character of their application.

In the synchronous (UBS) and wing (UBK) versions was realized remote control of the system of recharge in the case of the appearance of delays in the shooting in air with the use of the compressed air.

This was the first in the Soviet aviation system of the pneumatic recharging of machine gun, which considerably facilitated its operation in field conditions. In connection with the impossibility to use pneumatic recharge on the turret machine gun (UBT) because of the overall sizes of emplacement designer G. I. Nikitin developed for it retracting handle lever type. In the course of tests the machine gun UB worked smoothly even at the 9000 meters in altitude height , it continued to shoot in steep turns, chandelles, loops and dives.

Weight of the machine gun UB in the synchronous version 21,45 kg, wing 21,14 kg, turret 21,43 kg.

Rate of fire in the synchronous version 700 - 800 rp./min, wing and turret 900-1050 rp/min.

From 7 January through 22 February 1941, the machine gun Berezin successfully underwent troop tests.

UBT, Ilyushin il-2M





On 22 April, 1941, the general-purpose machine gun of Berezin was accepted into the armament of VVS. 12,7 mm machine gun UB ripened in time, since the war begun in two months revealed the ineffectiveness of 7.62-mm aircraft machine guns in aerial gunnery. The production of machine guns UB was conducted on Tula weapons and Izhevsk the Machine Building Plants. In 1941 were released 6300 machine guns UB, in 1943 43690, in 1944 38340, 42952 in the year 1945.

The synchronous machine UBS was used on the fighters I -15, I -153BS, Yak-1b, Yak-3, Yak-7b, Yak-9, MiG-3 and LaGG-3. The turret machine gun UBT was established on the bombers SB, P -2, Yer-2, Il-2, Tu-2, Il-4 and Pe -8.

UBS in Yak-9 .

[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.

The ShVak 20 was fed by desintegrable metalic belt and revolving drum, it was operated by gases taken by a port amid barrel.

2 times 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]

3 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 from part of 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.