On June 22nd, 1941, the German-led Axis forces invaded the Soviet Union, turning Germany's fortunes forever. By this time, the ZiS-2 had been in practical service through some 370 units in circulation. However, the 57mm projectile was a new adoption by Soviet forces and this meant that industry had to manufacture a completely foreign round for active combat service. When pressed into battle, the projectiles were reportedly weak against the middle-generation Panzer tanks being fielded by the Germans. This led to a re-adoption of 45mm anti-tank guns instead and a premium placed on development and production of the more potent ZiS-3 gun series. Production of ZiS-2 guns was halted for the remainder of 1941 and none were produced in 1942.
When the need for more guns prevailed, manufacture of ZiS-2 guns was reactivated in 1943 and this ran into the end of the war in 1945. During this period, an additional 9,645 guns were completed bringing total manufacture of the series to 10,016 units. The new-model guns were redesignated with the "Model 1943" name though they largely remained the same weapon.
Despite its anti-tank prowess by classification, the 57mm ZiS-2 could do little against the more advanced tank designs emerging out of German factories - namely the Panzer V "Panther" medium type and the "Tiger" and "King Tiger" heavy types - which required at least the Soviet 76.2mm projectile to pierce. As such, the role of the ZiS-2 gun was drastically reduced as the war winded down in 1945 and, in the post war years, it was only under issue with Soviet airborne forces due to its compact size and manageable weight. Some wartime models were installed on existing chassis to generate make-shift tank destroyers - as was the case with the ZiS-30 of 1941. However, this was more out of desperation due to the fast German advance on Moscow and the loss of so many armored vehicles in the fighting. This particular vehicle development mated the ZiS-2 gun with an outdated artillery tractor chassis which, thankfully, was limited to just 100 units or so.
The SU-57 Self-Propelled Gun was born from the simple mating of the 57mm anti-tank gun with the chassis and running gear of the American M3 Half-Track. 57mm AT guns (ZiS-4 L/37) fitted to T-34 tanks produced the "T-34/57" designation which saw limited production numbers. Captured ZiS-2 guns by the Germans were reconstituted as the PaK 208(r).