During the winter of 1942–1943, the 257th fought in the Battle of Velikiye Luki to destroy the German garrison of the city, which was captured on 17 January 1943. For the battle in the city, the division trained extensively for urban warfare, practicing attacks upon mock German fortifications built from snow. Dyakonov created five assault detachments of up to a hundred soldiers from the personnel of the division, consisting of sappers, machine gunners, mortarmen, smoke screen deployers, artillerymen, and "Ampulomet" throwers. Each detachment included reconnaissance, assault, support, reinforcement, and reserve groups. The assault on the city began at 10:00 on 13 December with a "Katyusha" rocket salvo, followed by artillery preparation. The 357th and 257th Rifle Divisions attacked from the west, while the 7th Estonian Rifle Division attacked from the east. The artillery fire proved ineffective due to poor visibility and unsuppressed German machine gun fire brought the infantry to a halt. However, the assault groups of the 257th continued the attack with relative success, crossing the Lovat. The infantrymen followed the assault groups, clearing the remaining German centers of resistance. Due to lack of preparation, the 357th and the 7th Estonian Rifle Divisions, who attacked with reinforced battalions instead of assault groups, failed to achieve their objectives and the city was not captured by the target date of 16 December.