This question has perplexed me for awhile, and not sure if it fits here, but hopefully someone versed in Cold War equipment and tactics could answer.
Why was the SKS rifle even manufactured and issued in such mass scale if the AK47 was to replace it so quickly? Both used the same intermediate cartridge, but the AK Seem infinitely more useful and flexible than the SKS carbine. Was this due simply to simple bad luck (like, the SKS being planned, but the AK rapidly developing), or due to some sort of strategic decision (long range rifle and “submachibe gun”).
Likewise, client states of the Soviet Union were often granted permission to manufacture soviet arms. In these countries, we also see manufacture of the SKS (East Germany, China, etc) while the AK existed and was being manufactured. Why would this happen, was it due to quirks in how the Soviets handled technology sharing, cost of manufacture, or some sort if “tactical” reasoning?
This came about because of an odd article I read that stated that the PLA during the Sino-Vietnamese War encountered issues because their army mostly consisted of SKS armed soldiers, with AK pattern rifles reserved for NCO’s. However, their NVA opponents were armed with entirely AK’s (Chinese supplied, at that!).
Given that in Chinese terminology, both the SKS and AK were designated “Type 56”, and were adopted at the same time, this just seems like a crazy choice.
So the SKS was made to replace the old Mosin Nagant as the main weapon for the Soviet foot soldier. It was finally developed and deployed by the end of the 40s. However the AK was already being made and basically outdated the SKS before really being deployed. So now the Soviets have a bunch of these rifles and factories ordered to make them. So now the question is what to do with them? Well they sold them or gave them to their satellite states and allies. This would now arm them with guns that were somewhat modern and they wouldn’t have to use old bolt action rifles or other outdated small arms. They could also give out licenses or let them make their variant of the SKS until given permission to make the AK.
This was also used in second line soldiers, guards, and other soldiers away from fronts. It was used to just give these guys a weapon while frontline troops got AKs. It frees up more AKs to troops who would be fighting, but wouldn’t leave the other troops unarmed who wouldn’t usually see action.
Originally, the SKS was to replace the Mosin Nagant (main service rifle), and the AK to replace the PPSh/PPS (NCO weapon). After the Soviets realized the AK was mostly better, they switched their main service rifle to the AK. The Chinese, choosing the early Soviet model, thought that the extra accuracy of the SKS would be useful at long rangr, with the NCOs and machine gunners providing rapid fire when needed. Naturally, they found out the hard way that the .5 MOA difference between the SKS and AK was negligible compared to having a 30 round magazine fed, select fire rifle.
Besides China, most other countries only adopted it for ceremonial or police use, notable examples being the (beautiful) East German Karabiner S and Yugoslavian M59 and M59/66.