"A program of trials of 40 mm English high explosive fragmentation tracer AA shells in tank guns
- Goal of trials: to establish the possibility of using 40 mm AA shells in a tank gun. Before trials, the following work is done:
- The 40 mm shell is disassembled.
- The possibility of firmly loading an AA high explosive fragmentation shell into a tank shell casing is tested. The firmness of the load is tested by loading the shell into a tank gun.
- The tank gun rifling and shell driving band are measured in order to discover the necessary forcing of the band for satisfactory loading of the shell (not having the driving band prematurely stick into the rifling).
- The maximum pressure the shell can bear is calculated by examining mechanical characteristics of the shell and its size.
- Supplies for trials:
- System: 40 mm English tank gun.
- Shell: 40 mm English AA high explosive shell.
- Casing: from the 40 mm tank gun.
- Propellant: propellant from the English AA shell and domestic propellant with ballistic characteristics close to English 40 mm shell propellant.
- Trial process:
- Discovery of the propellant load to achieve V0=790 m/s and pressure less than the maximum acceptable pressure calculated in point 4.
Note: according to information possessed by Artkom, the maximum acceptable pressure for the 40 mm AA high explosive fragmentation tracer shell is 3000 kg/cm^2. This information needs to be confirmed.
- Discovery of the propellant load to achieve V0=790 m/s using domestic propellant following points 1 and 3. Propellant will be tested on inert shells. If it is not possible to disarm the shells, testing will be done on shells that are incompletely armed with an inert detonator.
If it is not possible to achieve a velocity of 790 m/s without surpassing acceptable pressure, trials will continue with the maximum velocity attainable at this pressure.
- Further trials will be carried out according to typical testing procedure applicable to HE shells (aside from point 1), using the propellant load established in these trials. Increased pressure is considered 1.1 times the current working pressure.
The trial report should include data for the formation of ballistic tables. The report should also include English markings on the 40 mm shells."