A versatile heavy gun-howitzer used at corps and army level for long-range bombardment and direct assault fire alike, the ML-20 was powerful enough that its barrel was adapted almost unchanged for the SU-152 and ISU-152 self-propelled guns, becoming the terror weapon Soviet troops nicknamed 'Zveroboy'.
152mm howitzer-gun M1937 ML-20Vitaly V. Kuzmin · CC BY-SA 3.0 · sourcePicture taken by myself, Mark Pellegrini, at the United States Army Ordnance Museum (Aberdeen Proving Ground, MD) on August 14, 2007.Mark Pellegrini · CC BY-SA 2.5 · sourceSoviet 152mm mm ML-20 gun-howitzer, displayed in Hämeenlinna Artillery Museum. Photo taken on June 18, 2006. Source: Photo by me, User:Balcer.Balcer~commonswiki · CC BY 2.5 · source