John,

It is one of the original 100 375H&H Magnum Mausers made for Mauser in 1998 by Gottfried Pretchl for the Mauser 100 year anniverary. 100 were also made in 416Rigby. This was before Sigarms came along aoon after and bought the Mauser name. For some reason unknown to me, Sigarms/Mauser made a new run of 100 each in the same caliburs. I believe their actions are also from Pretchl/Golmatic.

Erik