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