Soviet-made 120mm ML-20 Howitzer gun. The term "howitzer gun" refers to a combination of qualities from both artillery systems. The ML-20 owes its uniqueness to its projectile's angle of elevation and initial velocity. Before the creation of ML-20, this term was not used.
The ML-20's baptism by fire came during the fighting on Khalkhin Gol. Later, the weapon saw extensive use during the Russo-Finnish War, where it was used to destroy bunkers and pillboxes on the Mannerheim Line. It was the most powerful weapon among Soviet self-propelled artillery, including the SU-152 and ISU-152. Direct hits from its 152mm projectile would pierce the armor of any tank, and if it struck the tank's tower it would crush it entirely. There were battles when tank towers literally flew through the air.