My initial thought is that these scratches are coming from the cartridge dragging across the front of the magazine during feeding. Another possibility is that there is a burr on the front of the ejector port but I think that would just scratch the bullet and not the case.
Try feeding a case by dropping it into the chamber being careful not to have it drag across the front of the mag.
Edit: These scratches, unless they are really severe, are just cosmetic and won't effect accuracy.