I think the story on these is that they're I.O. rejects. You'll notice the buttstock and grip looks just like theirs, the front trunnion isn't even drilled, and the barrel is populated with roll pins.
I just got off the ph with CF. These are from I/O and are all American made parts. What's up with the over gassed? That scares me!
IO Inc. AK-47 update for 2013 | Firearms4u
I've read a few people with this issue over the years from IO parts. When you build a rifle, make sure you inspect it over time. For an overgassed rifle, the bolt carrier is slamming into the rear trunnion and will deform the rivets (and could bend the receiver). There are rubber stoppers you can add to give the carrier something softer to hit and you can replace the standard spring with a stiffer one (I think Brownell's and Midway carry them). The spring will require more energy to push. If you are still having problems, you need to reweld and redrill the hole to prevent the extra gas.