I recently set up a CZ 75 for IPSC and in the first match I shot I had some malfunctions. I made these changes to the extractor and no more malfunctions.
I am a professional pistol smith (so I hopefully know a little bit about this type of tuning
) and if our shop worked on CZ pistols this is how I would tune any customers extractor (we don't do CZ work as of now, this was a personal gun).
CZ enthusiasts seem to be a very DIY bunch, so I thought I would share this.
The extractor seems to be a common weak point on CZ pistols. If you are experiencing extraction issues you could have one or more of any number of contributing problems.
Probably most commonly, you may not have enough tension on the extractor to reliably pull the shell from the chamber and hold it in place until it can hit the ejector in the correct position. This is because CZ pistols do not have a cartridge pocket on the breechface like nearly every other design so there is nothing to locate the case vertically on the breechface except the extractor tension. If you have too little tension the case can slip down the breechface and either ride under the ejector (causing a jam) or not impact it in a location on the case rim that will allow positive ejection (causing a stovepipe); both of these obviously cause feeding and extraction issues.
The modification in the last pic will create an artificial cartridge pocket using extractor tension and will help keep the case located in the proper vertical position on the breechface.
This is how I tuned my own extractor and it fixed MY problems, I of course can't guarantee that doing this will fix any problems you are having.
I also obviously can't guarantee that doing this won't harm your extractor unless I was doing it myself.
Basically, modify your own guns at your own risk
Luckily, in the big picture the CZ extractor is not an expensive part and these are not hard modifications to make.
These modifications were made in conjunction with thoroughly polishing the breechface with very fine sandpaper and polishing the wall of the breechface where the rim of the case would sit opposite the extractor. The inside of the hook and the slot behind the hook where the case rim would ride were well polished with very fine sandpaper WITHOUT CHANGING THE ANGLES OF THE BACKSIDE OF THE HOOK OR RAMP... The idea is to lightly smooth out (but NOT necessarily completely remove) machine marks without changing angles.
This may not need to be done on every gun...
This change in angle should be subtle, no more than a couple degrees. I may have been a little more aggressive on mine than I needed to.
Remember, if you attempt this; take things slow, use very fine sandpaper for polishing (1000 and 2500 grit is what I used), don't change any angles except what is shown in last pic (I used a diamond tool (E-Z-Lap) for that with the extractor secured in a vice), modify at your own risk.
Gratuitous completed gun pic