Don't bother, 3 thou' wont make much difference and you will probably find the ,308 bore up to a thou' oversize anyway. I've tried the Lee .312-185 in both my 7.5 Swiss (.3091") and my 7.62 (.3078") and the problem in both cases was the nose was too large and at any practical seating depth they still wouldn't chamber. The Lee 200 gr. shoots superb in both rifles by the way.