One additional refinement that you might be interested in trying is to also use Chris Long's optimal barrel timing (OBT) method to identify the 1 or 2 velocities where you rifle is most accurate and make sure you include those in the velocities you hit with whatever method of load workup you follow.
Just search for Chris Long and OBT, go to his wesite and read his paper. You will need QuickLoad and a chronograph to do this however. Using this approach I've developed accurate loads in as little as 9 shots and I've never found a rifle I couldn't get to 1 MOA or better no matter how pitiful it was. It does take some experience to figure out what really matters but that, of course, is half the fun. Good luck.