Even rarer than a British proofed 303 Mauser in intermediate action ! A Oberndorf Mauser in 303 that never made it to British shores, sance British proofs, only German complete with bore diameter in mm stamped on the underside of the barrel in front of the front ring. According to Speed these were mostly trashed in factory as test rifles thus few made it into the market place. I have included pics of the slanted mag box for the rimmed 303 cartridge as well as the opened bolt face for the cartridge base