for 5.56 these work great. There are 3 of us that have the vz 58 with these adapter and they run any AR mag LAR XCR 10 round mags. never a malfunction. forget last round bolt open though, even though they come with a bolt catch, they will jam up as they dont always catch the follower and the bolt will ride over it mushrooming the head. Best thing you can do is grind off the tab that is supposed to catch the follower. This way you can manually lock the bolt back with it. CSA said they only tested the mag catch with 3 types of high quality mags so don't guarantee its operation on any other mags.
http://www.wolverinesupplies.com/det...l-Adapter.aspx