A little excited, since I bought a cz85 and conversion kit together from gunbroker they were great except that the kadet would fail to extract about once per magazine 1/10. Empty casings would get in between the top of the ejection port and the extractor, sometimes they would wedge themselves behind the ejector. Well awhile back someone had an old post on a cz forum, telling you how to file the extractor, but all the pictures were gone as the opst was too old. I wanted to try it but figured it would be prudent to take it to a smith. Today I decided to do it myself based on the description. The problem is that the ejector face is perpendicular to the bore causing the round to stay straight in line with the bore as it is ejected. This allows the case to be able to get caught by the bolt if the case does not come off the extractor just right. By filing the extractor face 5-10 degrees back you angle the case's ejection slightly and prevent it from being caught up in the port. Today 100 rds and no failures, tomorrow I will try some more and report back. On this guy's post about ten other people described the exact same problem and any who tried this reported success. If you have questions I'd be happy to describe it more.