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Guns images
Updated on December 20, 2003                                    file name: guns.html
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The most of MiG-3s were armed with three syncronized guns over the nose: 
  • one UBS 12,7 mm machine gun on central position, 
  • two smaller ShKAS 7,62 mm machine guns on its sides.

This image shows some details of I-200, probably no.02 or 03, and are representative of early MiG-3s too. 
Late type MiG-3s had an unique large panel over the engine.
There is one UBS machine gun on central/left position, and two ShKAS on the sides.
The image shows the gun barrels, enclosed within thermal sleeves to avoid icing. Note their oblique front profile.
Thin pipes (?) arrive to the UBS, probably for pneumatic reloading.
The sleeves are supported by  two trasversal tubes fixed to the engine.

 UBS 12.7

 The Universal'ny Berezina Synkhronny (Universal Berezin Syncronized) was developed since 1940 into four versions:
UB - multipurpose by Berezin, Universal'ny Berezina;
UBS - synchronized, Synkhronny;
UBK - wing mounted, Kryl'evoj;
UBT - or turret, Turel'nij;
The UBS fired the 12.7x108 mm round  at a rate of 1000 rpm, at a muzzle speed of 860 m/s; it weights 21.5 kg
It was an highly effective weapon.

ShKAS 7.62

The ShKAS, Shpitalny-Komaritski Aviatsionny Skorostrelnij (Shpitalny-Komaritski rapid fire machine gun for aircraft)
was the standard 7,62 mm gun since 1935.
It fired the 7,62x54R round at a rate of 1800 rounds for minute, at a  muzzle speed of 825 m/s; the weapon weights 10 kg, and existed both for fixed fighter installation and with handle for defensive installation.
This weapon was not too effective against bombers, fighters and armoured vehicles because its lack of penetration into armoured plates.


Another shot of both weapons ( here the ShKAS has the handle for some defensive installation; by Lee Jong Tae).


Here are the gun firing slots on the nose of three-guns-armed MiG-3s.
Note again the obliquely shaped protruding thermal sleeves.

Here is a cutaway of the fuselage, giving a good idea of the armament and ammo boxes mount.
There is one UBS machine gun on central position, and two ShKAS on its sides.
The UBS ammo box is in front of the front fuel tank; the cartridge case discharge is on the left side.
The ShKAS ammo boxes  are in oblique position, one for each side of the aircraft. All the guns receive the ammunitions from the right side; for this reason, the left ShKAS ammo box appears in a more internal position than the right one, and the guns position is asymmetrical.
Metal wires pass from each gun to a handle on the instrument panel, to move the gun breechblocks; these wires pass throught a curved firewall separing the instrument panel from the guns bay.
Some thin levers between the engine and the guns should be for the syncronization mechanism.
A shell expulsion slot was on the left side of the water cooler fairing.
This good image shows some details of the gun bay:
  • the larger alluminium duct should be for wasted cartridges expulsion of UBS;
  • the thinner alluminium duct should be for left ShKAS ammo supply;
  • the curved firewall behind the guns is broken;
  • note the black fuel tank behind the ammo cases.
Photo copyright Jan Koennig
The image shows the nose of an early MiG-3; we recognize:
  • the guns and their ammunitions (out of the boxes), and the thermal sleeves;
  • the oblique ShKAS ammo box;
  • the curved firewall in front of the instrument panel and the wires for gun breechblocks;
  • the antenna mast, fixed to the internal structure (not to the cowling!);
  • the tubes of the structure, and the shaped plates on them for external panels fixation by Dzud locks.

The panel hold by the German soldier is from an early MiG-3; it goes over the engine, not on the gun bay as it could seem from the photo above.
The same image shows:
  • the curved firewall separing the cockpit from the gun bay; the wall is crossed by the gun firing and arming wires.
  • shaped metallic plates fixed on the steel tubes structure to fix removable panels by locks;
  • some small supports for panel fixing on the symmetry plan of the aircraft;
  • The ammo coils for UBS and ShKAS.

Here is a photo showing the inner face details of a side panel.
The color looks slightly darker than the external face; it could be the same green of the exterior face (but not faded by sunlight), or dark grey A-14.
The shape of internal structure of panels can be extrapolated, when not visible on photos, from the rivets lines visible on some good drawings.

Photo copyright Jan Koennig


From February 20, 1941, a new version with two further 12,7 mm  BK guns  on under-wing pods with 145 rounds each                                                 The new standard revealed itself unsatisfactory, as the weight increased of about 150 kg, deteriorating the flight characteristics of the aircraft; besides, the firing at high g manoeuvres was imprecise due to torsion flexing of the wings, so the most of the gun pods were removed when the aircrafts arrived at the units. 
821 examples with 5 guns were produced through July 27, 1941, when the under-wing guns were deleted from production, and the armament returned to the original standard. 
The predisposition for under-wing guns pods (i.e., reptangular panels for ammo visible under the wings) seems to have remained on following aircrafts too, and it looks to have been suppressed only towards the end of MiG-3  production. 
this image shows an underwing pod, without the gun barrel protruding from it. We see the opened ammunition door too, and a distorted landing light panel. Some undercarriage structures appear distorted too.
The aircraft is an early one, without slats.
Note that the pods are painted separately from the wing.
(image from Ian Konning)

here are two details of an image showing underwing gun pods with barrels protruding. The aircraft is a late production aircrafts, with slats and gun predisposition.
The shells expulsion slot should be on the left side of both pods.

315 late production examples were armed with 2 UBS with 700 rounds each, instead than the usual armament. 
Here is an image of the internal arrangement. 
The ammo boxes were probably disposed on the lateral positions previously occupied by ShKAS, but moved rearwards as the original UBS and extended downwards into the space left free by remotion of the ShKAS ammo boxes.; both UBS should receive their rounds from the right side, and expell wasted cartridges on the left. 
What we see on the photo are probably wasted cartridges ducts.
It is not clear if MiG-3s armed with two UBS were externally distinguishable from usual ones armed with three weapons; probably they weren't.

About 50 late production MiG-3s were armed with a couple of ShVAK 20 mm guns; their general layout can be supposed as for the 2 UBS armed aircrafts.
The ShVAK gun was designed and first built in 1936, and utilized an operating system similar to that of earlier ShKAS.
Rate of fire: about 800 rounds for minute
Weight: 42 kg
Overall lenght: 1,76 m
Barrel lenght: 1,25 m

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