The screw should absolutely be flush with the frame. There are times when the screw needs to go in at an angle in order to properly reach the threads in the magwell. This is entirely dependent upon the screw hole on the frame, which always varies. That being said, if it is difficult to remove the screw, you may have forced the screw in at the wrong angle which can strip the magwell threading. Please let us know if this occurs and do not try to back out the screw. We will not process a return or exchange for magwells with stripped screws.