Many CRF rifles have a bevel on the front edge of the extractor so it will easily cam over the rim of a chambered round. The pre-'64 Winchester Model 70 is a good example, but it's easy to do on a 98 Mauser extractor too. Otherwise 98 extractors won't go over the rim of a chambered case, though there are exceptions.
Some ammo has more of a bevel on the back edge of the rim, which can also help.
Maybe CZ put a bevel on the extractor of 527's in the past few years, or maybe one simply got skipped during manufacturing.
I believe the extractors of both my Brno ZKW-465 (the forerunned or the CZ 527) in .22 K-Hornet and my 527 .17 Hornet will snap over the rim of a chambered round, but now I'm gonna have to try both to make sure....
