T-28 armed with 85mm long-barrel gun (1939)
T-28 armed with 95mm long-barrel gun (1940)
http://ru.wikipedia.org/wiki....B5.D0.B 5.D1.81.D1.8F_.D0.BD.D0.B0_.D0.B1.D0.B0.D0.B7.D0.B5_.D0.A2-28

Cyganov's BT, project No. 2 fast tank (1934)
http://www.aviarmor.net/TWW2/tanks/ussr/bt-tsyganov_pr2.htm
Armour: ?
Armament: 45mm gun(?);
Maximal speed: 105km/h

SU-3 / T-27K self-propelled gun (1933)
http://www.aviarmor.net/TWW2/tanks/ussr/su-3.htm
Self-propelled gun build on T-27 tankette chassis
Armour:
Front: 10mm
Armament: 45mm gun OR 76mm gun OR 76mm recoiless gun. OPTIONAL: 2 x 132mm RS-132 Rocket Launcher.
Version with recoiless gun http://www.aviarmor.net/TWW2/Photo/USSR/su-3/t27_apk_2.jpg

BT-2 armed with 203mm Kurchevsky Recoiless gun
http://lib.rus.ec/i/62/164662/i_067.jpg
Armour: 203mm recoiless gun

T-100-Y heavy assault self-propelled gun (1940)
http://www.aviarmor.net/TWW2/tanks/ussr/t-100y.htm
Armour:
Front:60mm
Side:60mm
Armament: 130mm B-13 L/55 naval gun
Engine: 890HP GAM-34-BT, 12-cyl. (used on torpedo-boat)
Maximal speed: 32km/h (road)
Mass: 63,9t

Additional info:
SU-14 with 152mm gun
Range of fire=27km

Added (2011-03-11, 4:44 PM)
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1st Russian project of superheavy (>80t) "tank"
"Mendeleyev's Tank" self-propelled gun (1911)
http://www.aviarmor.net/TWW2/tanks/ussr/pr_mendeleev.htm
Armour:
Front:150mm (Turret: 8mm)
Side:100mm
Armament:120mm Canet gun; 1 x Maxim MG (Turret);
Ammo:51
Maximal speed: 14km/h
Mass: 173,2t

Added (2011-03-12, 9:58 PM)
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1st Russian project of breakthrought tank
Troyanon's Breakthorought tank (1916)
http://www.aviarmor.net/TWW2/tanks/ussr/troyanov_pr.htm
2 chassis - one front, one back (as a british Pedrail), on each steam engine.
Armour:??
Armament: 203mm gun (turret); 2 x 152mm gun (turret);
Engine: 2 x 1500HP

1940 soviet project of superheavy tank
VL ("Vladimir Lenin") (1940)
http://www.aviarmor.net/TWW2/tanks/ussr/vl.htm
Armour: max. 125mm
Armament: 130mm B-13 naval gun + 2 x 76,2mm + ? x DT mg OR 305mm B-23 gun (start velocity: 638m/s) + 2 x 76,2mm + ? x DT mg OR 130mm B-13 naval gun + 2 x 45mm + ? x DT mg OR 305mm B-23 gun (start velocity: 638m/s) + 2 x 45mm + ? x DT mg
Ammo: 100 (305mm); 100 (130mm); 300 (76,2mm);
Mass: 260...460t (few variants)
Engine: 2400HP
This project have gun of biggest kaliber of all of tanks of 1939-45 War - 305mm... (Ratte - 280mm, but 2 x 280mm).
In my opinion: this project is a result of Talvisota (1940), when soviets can't break Mannerheim-linja.

Added (2011-03-19, 10:38 PM)
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KV-1K (object 230) heavy tank with rockets launchers (1942)
http://forum.bestway.com.ua/showthread.php?t=4150
Armour: max. 95mm (including "ekrany")
Armament: 4 x 82mm rockets(?) [in boxes over tracks] + 76,2mm ZiS-5 + 3 x 7,62mm DT mg;
Maximal speed: 35km/h (road)
Production: few prototypes in 1942 (source: http://www.redtanks.bos.ru/kw1.htm )

Added (2011-04-18, 8:43 PM)
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KV-4 http://alternathistory.org.ua/tyazhelyi-tank-kv-4-sssr

KV-4 S.Fedorenko - multiturret tank, project (1940)

KV-4 (K. Buganov) - breakthrought tank, project (1940)

KV-4 (G. Kruchenikh) - multiturret tank, project (1940)
Mass: 107,7t
Armour:
Front:130mm
Side:130mm
Back:130mm
Turret:140mm(side)
Armament:
107mm ZiS-6 + 45mm 20-K + 4xDT
Ammo: 105 x 107mm, 300 x 45mm

KV-4 (F. Marishkin) - multiturret tank, project (1940)

KV-4 (G. Moskvin) - multiturret tank, project (1940)

KV-4 (N. Strukov) - multiturret tank, project (1940)

KV-4 (Ya. Yermolayev) - multiturret tank, project (1940)

KV-4 (L. Sichyev) - multiturret tank, project (1940)

KV-4 (L. Pyeryevyerzyev) - multiturret tank, project (1940)
Mass: 100t
Armour:
Front: 125mm
Side: 125mm
Back: 125mm
Armament:
107mm ZiS-6 + 45mm 20-K + 4xDT
Ammo:
100 x 107mm; 103 x 45mm;
Max. speed: 39km/h

KV-4 M. Khreslavskogo - breakthrought tank, project (1940)
Mass: 92,6t
Engine: 1200HP
Max. speed: 45km/h
Armour:
Front: 130mm
Side: 125mm
Back: 130mm
Turret: 140mm (side)
Armament:
107mm ZiS-6 + 45mm 20-K + 3xDT mg

KV-4 (N. Dukhov) - breakthrought tank (1940)

KV-4 (N. Shashmurin) - breakthrough tank (1940)
Armament:
107mm ZiS-6, hull
76,2m, turret
? x DT

KV-4 (P. Mikhaylov) - breakthrough tank (1940)
Mass: 86,5t
Armour:
Front:180mm
Side:150mm
Back:130mm
Armament:
45mm 20-K, hull
107mm ZiS-6, turret
3 x DT
flamethrower
Ammo: 85 x 107mm; 150 x 45mm;
Max. speed: 50km/h

KV-4 (G. Turchanov) - breakthrough tank (1940)
45mm 20-K, hull
107mm ZiS-6, turret
? x DT

KV-4 (N. Tseig) - Breakthrought tank (1940)
Mass: 90t
Armour:
Front: 130mm
Side: 125mm
Back: 125mm
Armament:
107mm ZiS-6 turret
2 x 7,62mm DS mg
flamethrower
Ammo: 120 x 107mm

KV-4 kolektivniy project (P.Tarapatin, K.Kuzmin, W.Tariotko)
Mass: 88t
107mm ZiS-6 turret (130 degree turn)
45mm 20-K
Armour:
125mm (all)
Ammo:
20 x 107mm; 160 x 45mm;
Max. speed: 36km/h

KV-4 (V.Pavlov)

KV-4 (D.Grigorovich)

KV-4 (NN project I)
http://alternathistory.org.ua/files/231210_kv4_09.jpg

KV-4 (NN project II)
http://alternathistory.org.ua/files/231210_kv4_10.jpg

A-44, project (1941) [variant I]
http://alternathistory.org.ua/44-supertank-sssr-1941g
Mass: 29...29,5t
Armour:
Front: 75mm sloped
Side: 60mm
Back: 55mm sloped
Turret: 75mm sloped
Armament
76,2mm ZiS-5 + 4 x DT mg
OR
57mm ZiS-4 + 4 x DT mg
OR
76,2mm ZiS-5 + 2 x DT mg + flamethrower
OR
57mm ZiS-4 + 2 x DT mg + flamethrower
OPTIONAL 76,2mm+2DT ==> 107mm OR 57mm+2DT ==> 107mm
Ammo: 100 for cannon OR 90 for cannon + 15 for flamethrower
Maximum speed: 55...60km/h

A-44, project (1941) [variant II, III, IV]
Mass: 36t [II]; 40t [III]; 50t [IV];
Armour:
Front: 75mm sloped [II]; 90mm sloped [III]; 120mm sloped [IV];
Side: 60mm [II]; 75mm [III]; 100mm [IV];
Back: 30mm [II]; 35mm [III]; 40mm [IV]
Engine: 600HP OR 850HP
Max. speed: 59km/h [II]; 65km/h [III]; 53km/h [IV];

Added (2011-04-25, 10:31 PM)
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P.Yosohin's Tank - superheavy tank - 1942 (project)
http://alternathistory.org.ua/superor....lektrik
http://img12.imageshost.ru/img/2011/02/09/image_4d52f257e6d28.jpg
Mass: ~270t
Armament
2x152mm+5x76mm+2x23mm+3x12,7mm+14x7,62mm
Ammo
152mm - 160...200
76mm - 650...800
23mm - 1200
12,7mm - 4500
7,62mm - 26460
Armour: minimal 40mm; maximal 125mm
Engine: M-30 OR M-40
4000...6000HP
Maximal speed: 36...40km/h

Added (2011-05-14, 8:18 PM)
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Francais FCM F1 - superheavy tank - 1939 (project)
http://www.aviarmor.net/tww2/tanks/france/fcm_f1.htm
http://ww2drawings.jexiste.fr/Files....-F1.htm
Mass: 140...145t
Armament:
90mm+47mm+4x7,5mmMG
Armour:
Front: 120mm
Side: 100...120mm
Engine: 2x550HP
Maximal speed: 20...24km/h

Added (2011-05-30, 7:20 PM)
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T-28 conical turret (1940)
Produced: 12(?)
http://www.armchairgeneral.com/rkkaww2....ic1.jpg
http://www.armchairgeneral.com/rkkaww2....bp1.jpg
http://ww2armor.jexiste.fr/Files....28E.htm
Armament: 76,2mm L-10+5xDT mg
Ammo: 70x76,2mm
Armour (as T-28E, but sloped Turret armour):
Front: 80mm
Side: 40mm
Rear: 40mm
Maximal speed (road): 23km/h
Soviet Union produced only 12(?) T-28 conical turret, but produced too 111 T-28E (T-28 with additional armour), circa 80% of T-28E was used during defense of Leningrad.

Have any other country medium tank with 80mm armour in 1940?