That one uses AR mags as it is fitted with an aftermarket AR mag adapter. The .223 versions come from the factory with a different mag.
Contact http://www.moviearms.com/ They do warranty work for Czech Small Arms. They have or can get all the parts you would need. Don't be put off by the website, they know their stuff.
Zahal in Israel carry the AR mag adapters and other bits an pieces. They ship world wide and are fast and reliable.