I dont know. I got this one off gunbroker a few years ago. I wish I knew more about it. Who ever did it, did a really nice job. It has a blind type magazine and the boltface was welded and recut and it has a sako type extracter. the barrel is a j p sauer and sons mauser that has been bored and re sleeved. 1/4 octagon with a full length rib. shoots nice.