I have a CZ 527 in 223 I can single load a round in the chamber without using the magazine.
I also have a custom rifle built on a Mauser 98 action, the extractor claw has been beveled as Wyosmith described and it will chamber single rounds without feeding under the extractor claw.
Chris, you might want to contact CZ about your problem.
Best Regards
Bob Hunter
www.huntercustoms.com