If you adjust the MFT there should be no wear on the rail from the pin - you should be able to lift it and lower it with a finger and have it land in the same spot. The issue is likely over tightening the two bolts that secure the rail to the rail guide. Try loosening them both and get the rail on the center of the pin. Tighten one of the screws - do not over tighten. Raise the rail and tighten the other screw, again, be careful not to over-tighten. It should raise and lower without an issue. Over-tightening will cause the rail to skew on way or the other.