The name is Rogak as mentioned above. I've never seen a Rogak in person, but it is based off of the Steyr GB, but they are not exactly the same. I’ve recently been playing a bit with a friend's Steyr and they are quite nice. However the operating system relys on good machining on the barrel OD and the barrel bushing ID. Without that it will be just a blowback.
The Rogak is reputed to not have the same quality of manufacture as the Steyr and that really hampered it’s reputation.