Fortunately, CZ guns are good with most brands. My CZ 527 sporter in .223 prefers Sellier and Bellot with a 55 grs bullet. If I can't find that, the Black Hills remanufactured load in 55 grs, and the PMP factory brand work the best.
The worst accuracy wise, Wolf brand, hard to chamber and hard to extract due to the lacquered case, and the tight chamber of the CZ. Remington is not so good, and Winchester white box just did not cut it. Which surprised me as the Winchester brand usually works really well in my other guns.
:-)