I recently acquired a Turk referb and would like to know what model Mauser it was origionaly? I would also like to know what ammo would be safe to shoot in it? I didn't take pick of the bottom metalbut, It does not have accomodations for capture screws. Hopefully the pictures will help. All numbers match as I tried to show in the pics. The 6th pic was of the rear of the barrel that has "7.91" stamped on it. I assume that is the caliber. Any info will be welcomed.