If using a mec 600, I would try pushing the sizing collar down a little. Not enough to change the headspace but enough to possibly pull the diameter in. If its only .002, it might work. Not sure but worth a try.
The ring type sizers have the habit of pushing the brass head down toward the rim, where it effectively mushrooms the head, i.e. increases rim diameter.
If you have a steady hand, a stone in a Dremel can be lightly run around the inside of the rim cut to gain you those few thousandths that you need. That said, as others have suggested, the MEC super sizer would be my first attempt to solve the problem
