I posted what CZ actually says on the website, so that's probably the best source of info there is. From my CZ 527M manual it says, quote,
"Characteristics features of all versions are;
...
high functional reliability in all environments, even with ammunition made by various manufacturers and with different types of bullets."
Page 20
"Operating Instructions...
Ammunition
Use only factory manufactured ammunition of appropriate caliber, which are in compliance with CIP regulations, (International Commission of Firearms), or SAAMI, (Sporting Arms and Ammunition Manufacturers Institute Inc of the United States). The use of other cartridges could damage the firearm or cause injury to the shooter."
Page 22
This is ALL that is in my CZ 527 rifle manual which came with my 527M several years ago.