76 mm tank gun M1940 F-34

The 76 mm tank gun M1940 F-34 (76-мм танковая пушка обр. 1940 г. Ф-34) was a 76.2 mm Soviet tank gun used on the T-34/76 tank. A modified version of the gun, the 76 mm tank gun M1941 ZiS-5 (76-мм танковая пушка обр. 1941 г. ЗиС-5), was used on KV-1 tanks during World War II. Nowadays, the two versions are often referred to just by their factory designations, as "F-34" and "ZiS-5", respectively. The F-34 was designed before the start of World War II by P. Muraviev of Vasiliy Grabin's design bureau at Factory No. 92 in Gorky. The gun was superior to both contemporary 76.2 mm guns, Gorky's F-32 and the Leningrad Kirov Plant's L-11, but it was the latter that had already been approved for the new T-34 medium tank. The initial T-34 Model 1940 with L-11 was in production when Germany invaded the Soviet Union. The F-34 was ready for production, but Marshal Grigory Kulik's high-handed interference with tank appropriation had made the relevant bureaucrats too fearful of being arrested to approve the better gun. Grabin and the director of the Kharkov Locomotive Factory (KhPZ), the centre of T-34 production, conspired to produce the F-34 anyway, and began to install the gun on new tanks. The new T-34 Model 1941 tanks, which were issued mostly to company and platoon commanders, were immensely popular with their crews. Letters from tank units reached Stalin's State Defense Committee (GKO), which officially authorized production. Also, due to Kulik's meddling, the KV-1 heavy tank model 1940 had ended up mounting Grabin's older F-32 gun, making it more poorly armed than the T-34 medium tank. Chief Designer of Tanks Joseph Kotin convinced the GKO to allow the use of the F-34 gun on the KV-1 heavy tank Model 1941. The ZiS-5 was a version of the gun designed to better fit the KV-1's turret. In 1943, the thick armor of the new German Tiger and Panther tanks had rendered the F-34 gun obsolete, and experiments were conducted to find a replacement.