"I.V. Stalin factory #92
September 8th, 1941
To the Chief Engineer of the Chelyabinsk Factory, comrade Makhonin
We developed and are currently manufacturing a coaxial 45 mm gun for the 107 mm ZIS-6 gun mount. The DT coaxial machine gun remains in its old place.
The tactical purpose of such a weapon is obvious: to avoid wasting 107 mm ammunition on targets that could be defeated with a 45 mm gun.
As the factory doesn't have a KV-3 tank, the prototype will be installed in a KV-2 tank turret.
Your designer comrade Schneidman informed us that you are making a new turret for the KV-3. Due to the obvious advantage of having a 45 mm gun in the KV-3 and minor changes required to the turret as a result of using this mounting, we ask you to widen the gun port and change the frame and gun mantlet in accordance to the attached blueprints. We don't have blueprints for the new KV-3 turret and are still working with old ones, but that shouldn't matter in this case.
At the same time, we ask you to develop ammunition racks for 107 and 45 mm rounds in the KV-3 turret. For this reason, we attach a dimensional drawing of a 45 mm round.
Attached: draft drawing of the coaxial mounting on two pages, dimensional drawing of the 45 mm round.
Factory director Elyan
Chief designer Grabin"