Mehul

It looks to me to be a sporter rifle built upon a military action. I do not believe it to be an original Oberndorf sporter because of the straight bolt, sights, wood, and butt pad. Also, Mauser did not resume production of sporting rifles until 1920 and iirc they stopped stamping the date on the reciever after WWI. A nice rifle none the less and I wish your friend success while hunting with it.

Adam