The extractor does not capture the rim of the case until it is pushed over it when the case meets resistance from the chamber wall.
The bottom of the bolt face would need to be cutaway to provide controlled feed...same as those horrible Savage big bores.
As for the Sako extractors being used in 700's...I have used the same myself and they work fine...as do 700 extractors, where the Sako extractors shine is when the ppc case is used with a bushed 700 bolt face.
There really is not much new when it comes to firearms...bolts, at least.
