In October 1922, Koptsov entered the 46th Machine Gun Course at Stavropol and Vladikavkaz. He later transferred to the United Higher Military School named for the Central Executive Committee in Moscow. In 1925, Koptsov became a Communist Party of the Soviet Union member. He graduated from the school in 1926. In August of that year, Koptsov took command of a platoon of the 49th Rifle Regiment, part of the 17th Rifle Division at Nizhny Novgorod. Between March 1927 and September 1928, he served as an instructor platoon commander for preinduction training at the Bronnitsy Military Enlistment Office. Koptsov then entered a year-long military and political training course in Moscow, from which he graduated in September 1929, after which he became a company political officer in the 3rd Verkhneudinsk Rifle Regiment of the 1st Pacific Rifle Division in the Special Red Banner Far Eastern Army. Koptsov fought in the 1929 Sino-Soviet conflict during his service with the division. In 1931 Koptsov graduated from the Leningrad Armored Refresher Courses for Red Army Commanders. He became a company and then battalion commander in the 1st Tank Regiment of the Belorussian Military District.