One of the problems that plagues 721/722s is the ejector and how it interacts with the extractor. If the extractor has lost its springiness or the edge is worn, the case will just tip out of the bolt face when the bolt is retracted and sit on top of the magazine. If the ejector spring is weak, the case will just barely point out of the ejection port but not release from the extractor.
Modifying the extractor relief groove to accept Remington 700 extractors is a bunch of work in and of itself, but it can de done. Nowadays, I sell customers who are having trouble with their 721/722s the M16 style or Sako-style extractors and machine the bolt for them, it is trouble-free.