P5 soviet hand grenades
The RPG-40 was developed around 1940 by the Soviet's as a small, portable anti-tank grenade. It could penetrate anywhere up to 20 mm of armour with it's 760 grams of explosives. It was a very effective weapon unitl the German's improved their tank models, where it became redundant due to the fact that no tanks had less than 20mm of armour anymore. It was replaced shortly after in 1943 by the RPG-43.