Most American pistol shooters have been trained that our magazines should drop free from the gun during magazine changes.
This prompts a common complaint among American shooters with the CZ75. When the magazine catch is depressed the mags only drop and inch or so. After the initial drop, they remain retained in the gun until removed by the shooters off hand.
The reason for this is the magazine brake. It is a small piece of slightly bowed spring steel in the magazine well that allows the magazine to drop and inch or so but does not allow it to drop free of the gun.
If you would like to change this behavior in your CZ75 check out the CZ Full Magazine Brake ⇒ from CZ Custom ⇒. Replacement of the factory magazine break with this aftermarket replacement part should allow the magazines to drop free during magazine changes.
I believe that the 75, all steel 75B Compact, 75B, 75BD, and some of the 75SA guns have the magazine break as described above. I also believe that the 75B Tactical Sport, 75 Shadow T, and the 75 Compact SDP do not have the magazine break as described above. If your experience is different, please let me know.