"Report on the composition of tables of penetration for 122, 152, and 203 mm concrete piercing shells for A-19, ML-20, and B-4 systems
From April 17th to May 15th, 1941, ANIOP composed theoretical calculations for penetration of 122, 152, and 203 mm shells, and then tested them by shooting at the expected velocities. Work was done according to a program composed by ANIOP and confirmed by Deputy People's Commissar of Defense, Marshall of the Soviet Union, comrade Kulik on December 19th, 1940.
- Processing of experimental data from ANIOP records.
- Performance of trial shooting at 500, 1000, 2000, and 3000 equivalent velocities at plates 30 degrees from normal.
- Processing of data and composition of data tables.
- Processing of experimental data to determine the penetration of 152 mm, 122 mm, 107 mm, and 76 HE shells, and composing penetration tables for HE shells.
- 122 mm gun: NF 17/1 26/39 P
- 152 mm gun-howitzer: 15/7 TsA 18/39 Shuf
- 230 mm howitzer: 17/7 sb.21/40 Shuf
- Results are significantly lower than calculated. Shooting at 500 meters, the penetration is 102 mm with 203 mm concrete piercing shells (calculated: 154), 100 mm from 950 meters with the 122 mm gun (calculated 138 mm) and 90 mm at point blank with the 152 mm gun-howitzer (calculated 132 mm). HE shells penetrate 40 mm (107 mm gun model 1910/30) at point blank and 30 mm at 500 meters with the 76 mm L/40 divisional gun model 1902/30.
- The best penetration was achieved by the 122 mm concrete piercing 2-02819 shells. These shells can penetrate 5-6 mm more than 203 mm shells.
- When penetrating armour, both HE and concrete piercing shells shatter into fragments. The breach in the armour with the caliber of the shell counted as the penetration. In this case, the damage beyond the shell would be dealt by the fragments of the shell and the armour.
- Most experimental data points lie in the vicinity of a 2200 resistance factor armour plate, which is what was used in calculations."