Does happen, tho. When I got my WASR 10/63, I found the mag catch was too short, which allowed the back of the mag to move downward too far and somehow induced the rifle to try to feed too many rounds at once. Replaced it and works like a champ now.
I took an AK course from Sonny Puzikas back in May. He was using an AK-74 that would periodically fail to extract - the firing chamber had dirt buld-up in it. He finally traded it for another AK-74, explaining that he had been running the previous one without cleaning or lubing it to see how far it would go. So how far did it go? About 6500 rounds, he said.