During WWII, Russian soldiers used many varieties of anti-tank rifles including the Degtyaryov PTRD. The PTRD fired a 14.5mm armor piercing bullet which could penetrate the armor of German Panzer III and IV tanks at 100m. To counter this threat, German tanks were equipped with Schurzen armor. The PTRD was used to destroy parts such as periscopes of Tiger and Panther tanks that had heavy armors. It was also seen used in an anti-aircraft role.