Experimental Guns

"Decree of the State Committee of Defense #4851ss
December 27th, 1943
Moscow, Kremlin

On the design, production, and trials of experimental guns for tanks and SPGs.

The State Committee of Defense decrees that:

1. On the 85 mm tank gun: GAU chief comrade Yakovlev and Armoured Forces commander comrade Fedorenko must perform trials of the 85 mm S-53 and S-50 guns installed in T-34 tanks (S-53 in a T-34 with a stock 1420 mm turret ring, S-50 in a tank with a widened turret ring) and the 85 mm LB-1 gun designed by factory #92 in a T-34 with a widened turret ring before December 30th, 1943.
   Report to GOKO on results by January 2nd, 1944.
2. On the 100 mm tank gun (comrade Grabin):
1. NKV (comrade Ustinov) and TsAKB (comrade Grabin) must provide the S-34 100 mm tank gun for trials by January 1st, 1944.
   GAU chief (comrade Yakovlev) and Armoured Forces commander (comrade Fedorenko) must perform trials by January 5th, 1944.
   Report to GOKO on results by January 7th, 1944.
2. NKV (comrade Ustinov) and factory #92 director comrade Yelyan must produce two S-34 100 mm guns according to blueprints from TsAKB, one for the IS tank and one for an SPG on the T-34 chassis to factory #100 by January 25th, 1944.
3. NKTP (comrade Malyshev) and factory directors of Kirov factory (comrade Zaltsmann), factory #100 (comrade Kotin) and Uralmash (comrade Muzrukov) must design and produce an IS tank and an SPG on the T-34 chassis with 100 mm guns.
   Perform factory trials of the IS tank and SPG with 100 mm guns by February 20th and provide the tank and SPG for proving grounds trials by February 25th.
4. GAU (comrade Yakovlev) and the Armoured Forces commander (comrade Fedorenko), in cooperation with NKTP and NKV, must, within five days, perform trials of the IS tank and SPG with 100 mm guns and deliver a conclusion to GOKO by March 5th, 1944.
5. TsAKB (comrade Grabin) must include the possibility to install an 85 mm barrel into the S-34 mount to achieve a muzzle velocity of 1000-1100 m/s and begin the production of this gun with the aim of producing an experimental prototype for government trials by April 1st, 1944.
6. People's Commissariat of Ammunition (comrade Vannikov) must produce ammunition (casing, propellant, AP and HE shells) for the 85 mm TsAKB gun with a muzzle velocity of 1000-1100 m/s and provide 1000 proof rounds as well as 250 each HE and AP rounds.
3. On the 130 mm tank gun (comrade Grabin):
1. NKV (comrade Ustinov) and TsAKB (comrade Grabin) must design by January 5th 1944 and produce by March 1st 1944 an experimental prototype of a 130 mm gun, with the ballistics of the 130 mm B-13 naval gun, to be used in an SPG on the IS chassis.
2. Director of factory 232, comrade Zakharyin, must produce a barrel with breech and other components, as well as cast and forged components, and deliver them to TsAKB by the aforementioned date.
3. NKV (comrade Ustinov) and TsAKB (comrade Grabin) must send one 130 mm SPG gun to factory #100 by March 10th, 1944.
4. NKTP (comrade Malyshev) and directors of factory #100 and Kirov factory must design an SPG on the IS tank chassis to use a 130 mm gun.
   Begin factory trials of the 130 mm SPG by April 1st, 1944, and provide it for proving grounds trials by April 5th, 1944.
5. GAU (comrade Yakovlev) and the Armoured Forces commander (comrade Fedorenko), in cooperation with the NKTP and NKV, must complete proving grounds trials in five days' time and report to GOKO with their conclusions by April 10th.
6. People's Commissar of Ammunition (comrade Vannikov) must produce 500 each of HE shells for the 130 mm SPG, AP and HE shells for the 122 mm gun with a muzzle velocity of 1000 m/s, and deliver them by March 20th, 1944 for trials.
4. On the increased muzzle velocity of the 122 mm tank gun:
1. NKV (comrade Ustinov), TsAKB (comrade Grabin), OKB-172 (comrade Ivanov) and factory #172 director (comrade Bykhosvkiy) must design and produce two prototypes of a 122 mm gun with a muzzle velocity of at least 1000 m/s using a 25 kilogram shell (one designed by TsAKB and one by OKB-172) to be used in an IS SPG.
   Submit finished prototypes to factory #100 for installation in vehicles by March 10th, 1944.
2. NKTP (comrade Malyshev), Kirov factory director (comrade Zaltsmann) and factory #100 director (comrade Kotin), in cooperation with TsAKB and OKB-172, must design IS SPGs with TsAKB and OKB-172 122 mm guns.
   Finished SPGs must be submitted for proving grounds trials by April 1st, 1944.
3. GAU (comrade Yakovlev) and the Armoured Forces commander (comrade Fedorenko), in cooperation with the NKTP and NKV, must complete proving grounds trials of the SPGs within 10 days and submit their conclusions to GOKO by April 15th, 1944.

Chair of the Committee of Defense, I. Stalin."

RGASPI 644-2-254

KV-100 Trials

Not much is know about the KV-100, just one photograph of a KV-85 with an S-34 gun, only that it did not make it into production. Here are some pretty good reasons why.

"To the Chief of GAU KA, comrade Yakovlev
Commander of the Armoured and Mechanized Forces, comrade Fedorenko
Copy to the Narkom of Armament, comrade Ustinov

The NKTP received:

1. A report on the gunnery trials of the S-34 100 mm gun installed in the KV-85 tank and
2. A conclusion of the commission based on results of the gunnery trials.

Having examined the documents of the commission, the NKTP deems it necessary to make the following comments:

1. Even though the notes claim representatives of the NKTP were present at the trials, that does not represent reality, as the NKTP was not invited to the trials.
2. The tank turret was not equipped with an an ammunition rack, spare parts and instruments, observation devices, and was not balanced. The resulting trials are unconvincing and incomplete.

In specific:

1. The established rate of fire cannot be accepted, as shells were not retrieved from an ammunition rack, but stacked in the turret bustle. Firing was performed with the hatches open, and the crew was especially trained, which should not be done during normal rate of fire trials. The commission claims that placing the ammunition on the floor is undesirable, considering the weight of 100 mm shells, but then it is not clear where the commission proposes this ammunition be placed, as a large ammunition rack on the floor is a common feature of all tanks.
2. Firing from the move was ineffective, the causes of which were not established. It is known that firing from the move is an exceptionally important feature of a tank.
3. The commission did not perform measurements of turret rotation on a slope. Considering that the gun turned out unbalanced and the turret was heavy after installing a 100 mm gun (the commission remarks on difficulty when turning the turret), it can be determined that the installation of an S-34 in the tank causes serious balance issues for the turret.

Aside from these problems, the commission itself pointed out several negatives, such as the cramped loader and gunner workspaces, the necessity to move the turret traverse mechanism, replacement of the sight and observation devices, ventilation of the fighting compartment, etc.

After all this, it is a little strange to see that the commission concludes that the S-34 100 mm gun should be adopted into use in tanks and SPGs.

The NKTP considers that these trials can be considered trials of the gun only, and do not indicate the possibility of installing the gun into a tank, as no complete effort was made to install the gun into a tank. The NKTP cannot agree with the commission's conclusion.

People's Commissar of Tank Production, Malyshev

February 9th, 1944"

CAMD RF 38-11369-490