Because of the relocation, Soviet production took almost a year to reach its full potential. The desperate battles of 1941 had to be fought largely with existing stocks of weapons and ammunition. Still, despite all its tribulations the Soviet Union produced approximately 6,590 tanks in 1941, two-thirds of which were T-34s and KV-1s, as compared to 5,200 tanks for Germany. The USSR also produced slightly more than twice the combat aircraft Germany produced, twice the number of guns, and eleven times the number of mortars as Germany. Some of these new weapons went into battle before they could be painted.
Once it recovered, Soviet industry became steadily more efficient. Unlike German weapons production, which constantly changed the design of tanks and other weapons to improve battlefield performance, the Soviets generally focused on more efficient production of the same basic weapons. By 1943, standardization and mass production meant that Soviet industry delivered weapons at an average of 60 percent of 1940 costs in terms of labor hours.