Neither action nor barrel were made at the Mauser, Oberndorf factory. This rifle was made and proofed in Suhl 11/28 = November 1928. At that time no one in Germany bought a new standard length action only from Mauser. The better Suhl gunmakers still had lots of unfinished actions in stock, left over from the 1915 – 17 “decentralized” making of Gewehr 98 and Kar 98AZ military rifles. These stocks lasted the better gunmakers like Meffert of the Suhl guntrade until WW2. Many more sporting rifles were made on scrubbed ex-military actions, but your rifle lacks the military arsenal workers marks under the receiver ring.
Commercial Mauser, Oberndorf actions intended for sale to other gunmakers were invariably marked with the full Mauser commercial serial number on the underside of the receiver and on the rear wall of the magazine. Here are three examples of such serial numbers.

The making of octagonal and half-octagonal, ribbed barrels waw a domain of the Suhl and Zella-Mehlis barrelmakers. There is strong evidence of Mauser buying in such special barrels from Suhl instead of machining small lots (for their factory) themselves.