After the October Revolution, he took the side of the Soviet government. He was elected by the soldiers as commander of the 26th Infantry Division. In September 1918, he was appointed commander of the Second Army of the Eastern Front. Shorin successfully reorganized the army and directed her actions in the Izhevsk-Votkinsk operation in 1918 during the spring offensive of Admiral Kolchak's troops. Since May 1919 he was the commander of the Northern Group of the Eastern Front, and led the Perm and the Ekaterinburg operations.