In Part 1 of this article, I wrote about the beginning of the Kalashnikov machinegun story, Part 2 was dedicated to the bureaucratic hoops he initially had to jump through, Part 3 described the technical triаls and competition between the Kalashnikov and his rivals, Nikitin and Sokolov.In this chapter, I will go into the story of troop trials that determined the destiny of Kalashnikov GPMG.The troop trials began in the summer of 1960.Four military units were chosen to test new machine guns.