I don't own a CZ, but I do have a .223. I would say 300 yds. is a good range for most guns in that caliber. They shoot nice and flat to there, then start to drop a little quicker. With the right ammo, my .223 will shoot half inch groups at 100.

By the way, yotes101, I notice your fairly new here, so welcome to the boards. I noticed your other post here didn't get a lot of responses. Don't worry. Sometimes it takes a while for answers to start coming in.