Later last year I posted a thread, which I cannot seem to find now, about the proof markings on a raised rib German built Belgian Mauser that I had picked up. It was proofed in 1933 and was marked a 7,8mm x 57. It was marked as being brooded with a 15gr. bullet.
The general consensus on the forum was that it was most likely a 8mm Mauser. But that it might have been the smaller .318 diameter.
I finally got around to taking a chamber cast, and was able to confirm it was a .323 diameter bore chambered in conventional 8mm Mauser. I was able to fire the gun and it had no issues. Just wanted to update on the matter for anyone who recalls the thread.
