These guys know their AK's. I'd recently purchased an AK/AR 10 hybrid to chamber the 7.62 x 39. Cheaper rounds that pack a punch. It was supposed to be a match made in shooter paradise. Unfortunately, it jammed multiple times with each magazine. I replaced the bolt and the firing pin. Cleaned it religiously with the hopes that a little love would correct the problem.
Finally, after months of frustration, I was set on selling it. I reached out to a friend who certified my wife on her CCW - Frank Oberg - and he recommended Frank at Marxman Arms. I took my rifle to him and he showed me exactly what the problem was by demonstrating with a Snapcap. He polished up the feed ramps and pointed out the marks the lips on the magazines were scraping the shell. I dremmeled out where he told me and took it to the range.
Voila! Fixed. Shoots like a dream. Take any of your AK issues (I know, I know - what issues) to Frank and he'll fix you right up!