I have a CZ 527 Varmint with Kevlar stock in .223.
It came with a pretty nice test target.
The worst group I shot with factory ammo at 100 yards when I first got it was 1.159.
Luckly, the first group that it ever shot with factory ammo was 0.245 and averaged 0.416 so I wasn't worried when that horrendous group occurred.
Turned out the rifle didn't like the weight and speed combination.
When I switched to hand loads, the picture got much more positive and hand loads shoot much better than with factory ammo.
Its top 25 hand loads average under 0.350 with bullet weights from 40 grains to 63 grains including target and hunting bullets. The average of every hand load I ever shot (1147 measured so far) is 0.534. And that includes all the loads that were at the low end of the load tables. My .223 seems to like to be in the high middle area of velocities.
I wouldn't be overly concerned about your CZ until you shoot it with a variety of ammos.
One of my range buddies has a .204 that also shoots very accurately and has a great record in dispatching ground hogs but it seems to have very strong preferences for bullet shape and velocity.
Don't be surprised if some ammo shoots really well and some others don't.