My M1925 Mannlicher – Schoenauer in 8x60 Magnum/S also has the front mount base dovetailed into the receiver ring. Through the last 20 years or so it never gave any troubles, though I shot about 100 heads of game with it, many more shots on targets. Recollecting, I must have sent about 500 bullets through it.

The Mauser, Oberndorf factory usually dovetailed their factory option scope mounts into the receiver ring too. Only quite recently European proofhouses frown upon these dovetail cuts, but this came only with the use of modern Magnum cartridges and the practice of many handloaders who try to squeeze .300 Mag ballistics out of a .30-06. Up to a few years ago, the proofhouses drove the scope base out of the slot to have a look beneath. Only if the slot was so deep to cut into the barrel threads, the receiver was rejected. If there still was solid steel in the bottom of the cut, the rifle was accepted for proof.