Well I imagine a receiver failure is pretty rare, if anything is small parts that tend to give out. I really want an AR but figure AK parts might be easier to come by during a ban because they are made all over the correct.
Yes extractors,bolts, and ejectors and most of the other small stuff that went into the reciever was still available. But the pistol grips and flash hiders and fixed bayonets was another thing though. Sure you could get them but putting them on said weapon resulted in a felony. So that is how the 922 regulations came to light. Where for I think every 3 foreign made parts you need a US made part for the build.