Do you realize just how miniscule 3 grains is? Assume you are shooting 60 yards. An arrow 3 grains heavier than another might hit 1" lower at that distance. Are you capable of shooting accurately enough to be able to tell the difference?

Sure, you wish the tolerance was better, but it's not. You've already spent the money for them. Tune your bow to shoot them and have fun. Worry more about the straightness of each shaft. Roll them on a table or something and check the runout. Often if they are crooked it's near the ends.

Take a .003 shaft such as the XT, cut about 1 1/2" from the nock end, the rest from the point end, and you end up with a shaft about as straight as one of the "Pros". Those 3 grains you're worrying about are never going to make a difference unless you're an Olympic shooter popping of 90 meter shots.