I have a used CZ75 SC Massada. The SC means that it has a full-size frame with a compact slide. Yesterday, I fired four cartridges, but it didn't fire the fifth cartridge. Subsequent pulls of the trigger didn't fire the cartridge. I ejected the cartridge thinking it was bad. However, all I saw was a tiny mark on the primer. I loaded up another magazine and tried again. Unfortunately, I had the same result, just a tiny mark on the primer. The cartridges fired successfully in another pistol. Am I correct to think that the firing pin broke or is there some other possibility? If it is the firing pin, should I go with a CZ factory firing pin or are there better aftermarket options?