ZiS-2

57-mm anti-tank gun model 1943 (ZiS-2)
ZiS-2 in the Kremlin of Nizhny Novgorod, Russia.
Type	Anti-tank gun
Place of origin	Soviet Union
Service history
Wars	World War II Lebanese Civil War
Production history
Designer	design bureau of No. 92 Artillery Factory headed by V. G. Grabin
Produced	1941, 1943-1945
No. built	10,016
Specifications
Weight	1,250 kg (2756 lb)
Length	7.03 m (23 ft 1 in)
Barrel length	bore: 3.95 m (13 ft 0 in) L/69.3 overall: 4.16 m (13 ft 8 in) L/73
Height	1.37 m (4 ft 6 in)
Shell	57×480 mm. R (AP)
Caliber	57 mm (2.24 in)
Breech	vertical block
Carriage	split trail
Elevation	-5° to 25°
Traverse	56°
Rate of fire	up to 25 rounds per minute
Muzzle velocity	1,000 m/s (3,300 ft/s)
Maximum firing range	8.4 km (5.21 miles)

The ZiS-2 (Russian: ЗиС-2) was a Soviet 57-mm anti-tank gun used during World War II. The ZiS-4 was a version of the gun meant to be installed in tanks. ZiS stands for Zavod imeni Stalina (Russian Завод имени Сталина, "Factory named after Stalin"), the official title of Artillery Factory No. 92, which produced the gun first.

In the beginning of 1940 the design office of V. G. Grabin received from the Artillery Department the task to develop a powerful anti-tank gun. The head of this department Marshal Kulik and its subordinates estimated that the use of heavily armored tanks by the USSR in the Winter War didn't go unnoticed in Nazi Germany and would lead to development of similar fighting machines there. There is also a chance that the department was influenced by the German propaganda about the experimental multiturreted "supertank" NbFz. To this vehicle heavier armor was attributed than it actually had. Therefore, Grabin and its office were guided by the characteristics of the domestic heavy tank KV-1 with 40–75 mm armor. In the opinion of developers, the optimal calibre in this case was 57 mm. The velocity and mass of the armor-piercing 57 mm projectile allowed it to attain sufficient kinetic energy to penetrate up to 90 mm of RHA while keeping the gun sufficiently light, mobile and easy to conceal. However the decision also had a downside: this caliber was new to the Red Army, so the manufacturing of the projectiles had to be started from scratch.

Development started in May 1940 and in the beginning of 1941 the gun was adopted as 57-mm anti-tank gun model 1941 (ZiS-2) (Russian: 57-мм противотанковая пушка образца 1941 года (ЗиС-2)). Production began on June 1, 1941 but on December 1st, 1941 it was stopped by marshals N. N. Voronov and G. L. Govorov, their explanation being that ZiS-2 shells go right through weakly armored German tanks without doing much harm inside. Other possible reasons for the decision were high cost of the gun and problems with shell production. By then, 371 pieces were built.