From what I can understand it is a replica of the Beretta A300. Watch the you tube video on the AL 391 reassembly. It helps. I haven't shot it yet . But fit and finish and function is good. Mags seem to fit and release fine. There is no bolt hold open function without a empty mag? If it goes boom and ejects as all my other Norcs do it will be one of the best buys CA has!!!