Case finishes - 7.62x39mm


Why is it that the copper washed and lacquered case finishes were in use at the same time by the Soviets and Chinese for the 7.62x39mm cartridge? I know that the LS finish is supposedly “cheaper”, but there has to be more to it than that. Perhaps the LS case finish was for ammunition to be used for training or export and the CWS was for wartime issue? I’d like to hear your opinions and suggestions. Also, why is it that the Soviet T-45 tracer is only ever found in CWS cases and ball will be found in CWS or LS? Other manufacturers of the T-45 use LS cases.