Does the 750 magazine for the 308 have the little spacer in it like the 7400/7600 magazines does? If it does, speaking from experience make sure that it is firmly in place. I had one that was angled slightly forward and it would cause the nose of the bottom 2 rounds in the magazine to hang on the front of the magazine. I have little tolerance for magazines that don't work and they don't stay around long, however since this is a new gun I would call Remington and request they make it right. Hope this helps