I shoot 600 yd and 1000yd competion with a 6.5-284 and I do a lot of sorting some of which may not be necessary.Some of the top shooters will not tell you everything they do,but I do every thing that I think might help me compete against those that are better shots than I. As to bullets in order of importance in my opinion: sort by bearing surface, tip the bullets(this increases bc a little and at the same time it uniforms the meplat) regardless of weather I tip the bullets , I sort by oal. Last I weigh looking for an oddball weight. Weight variance of .15 gr. is acceptable. ( .05 gr is almost equal to 1/10,000 of an ounce.
As to brass,weight to within .5 gr is definitely close enough, prob 1.0gr( as you get more firings brass will gain weight by retaining burnt powder residue) Most important thing for competition brass is to keep number of firings sorted to help with consistent neck tension or anneal) I hope to be annealing next year. AND don;t forget the usual processes to be consistent; uniform p. pockets,full length size bumping no more than .001, chamfer and debur and trim to length.Remember this caveat; long range accuracy is the results of consistency!