The mortar and grenade launcher proposed to GBTU USA are analogous in their design.
The main difference between these two devices are the caliber of the barrel and a lack of stoppers in the grenade launcher.
The grenade launcher's caliber is 57 mm.
The mortar's caliber is 52 mm.
The role of the stoppers in the grenade launcher is performed by a metallic plate that prevents the propellant charge from falling out. The metallic plate is screwed into the rear part of a wooden plank.
The mortar is simple to use and produce. Compared to the English design, it has many significant technical advantages, mostly a smaller amount of required parts and a simpler loading process.
The ballistic characteristics of the mortar (300-400 meters range for mortar shells, 200 m for grenades) is unacceptable. The mortar is designed for the 50 mm infantry company mortar round, which offers no advantage as that mortar has been removed from production.
The project proposes the installation of the mortar in the front of T-34 and KV-1S hulls instead of the DT machinegun. This solution, for obvious reasons, decreases the firepower of the tank instead of increasing it.
The mortar mount has several design flaws, which can be summarized as the following:
- No mantlet has been designed for the mortar mount. The barrel of the mortar is also not armoured.
- The mortar is easy to aim vertically and horizontally, but has no means of fixing its position. There is also no travel lock mechanism.
- Putting the mount outside of the tank increases the area of weakened armour.
Conclusions: the installation of a mortar in T-34 and KV-1S tanks instead of a DT machinegun as proposed by the factory #455 design bureau is not reasonable, as neither the mortar nor grenade launcher can adequately fight enemy personnel.
Chief of the 3rd USA GBTU Department, Engineer-Lieutenant-Colonel Kovalev
Senior Assistant of the 3rd USA GBTU Department Chief, Engineer-Major Vasilevskiy"