This man on video is on the hard drugs to say the least. He is delusional, he should be making stories for kids.
"Tokarev was a friend of Stalin", "two competing designers", "Stalin picked this or that..." , "Stalin had on his table a bunch of broken SVT-38s", "[skss] sent to Belorussian front", "in 1945 it was decided that SKS will be primary battle rifle". On historical facts about Soviet SKS his success rate was about 10% in this video (I stopped watching at some point - I mean I can't take that BS/min rate. ).