Here's a test with the CZ with factory ammo using Nosler 300gr. Partition from a non-weighted lead sled, it appeared.
Appears about 5/8" @ 100yds & with a low powered scope, so perhaps they shoot just as well as my 602 did.
I did shoot a friend's .375 602 a few years back, with factory Winchester 300gr. Silver Tips. That one did about 3/4"
with that old factory ammo. It chronographed 2,474fps. My own .375/06IMP(26"bl) shooting just after the 602, chronographed
2,472fps with 300gr. Sierra BT's and Norma 300gr. RN, both using 60gr. BLC2.

https://www.youtube.com/watch?v=3ZIs8l3T9-w