The story is.... Kalashnikov was a wounded T-34 tanker tinkered and designed the AK-47 while on convalescent leave.
Successful German Arms designer Hugo Schmeisser was captured and forced to work on Kalashnikov's design team
Schmeisser designed the Stg-44, which has a different bolt locking design, but is very similar to the AK-47 concept
Some say this is because Kalashnikov encountered Stg-44's on the battlefield, but I wonder how much of the design work was actually done by Hugo Schmeisser.
If Schmeisser designed it, I can imagine the Soviets creating this wonderful patriotic story of a wounded tanker designing it for his country.
Propaganda ???
Here is the Stg-44
It uses an intermediate cartridge, smaller than the K98 rifle but larger than the 9mm subguns
30 round magazine and select fire
The worlds first successful Assault Rifle....