I am sure some will disagree but here goes...... Probably the most accurate instrument you have in your toolbox is the micrometer or calipers. With that being said, keep the powder the same and do all the tweeking with the highly accurate calipers/micrometers.
Of course you will have to get comfortable with the pressure levels by keeping the seating depth constant (say .010 off the lands) and slowly increase the powder until you reach the pressure point where you want shoot your rifle. After you get where you are comfortable with the pressure, keep the powder the same and do all the tuning away from the lands in .005" increments until you find where the node starts for your barrel and keep going until you find where it stops. At that point, you will have defined the accuracy seating depth range for your gun and you should be basically done. Shoot inside this defined zone to find where the (1) accuracy is the best and (2) the velocity is the most consistent.
Most have powder scales that are + or - .1 grains and in the extreme, you could get almost .2 grains variance without seeing it and even much more dispersion when you actually are changing the powder charges in minute amounts. For the untrained, it looks as though there is an issue with the rifle when in reality, it could just be overlapping powder charges due to scale errors.....
For me, when I had the digital scale that was only good for .1 grains, I weighed the powder using the blinking method. Specifically, weigh the powder such that it JUST blinks to the correct value. This way you are minimizing the variance between powder charges. Of course, the easiest way is to get a more accurate scale (Acculab is accurate to .02 grains) and go -.000 and + .02 grains when working up loads.
FWIW, when using this method, we always get less than 10 FPS dispersion on velocity as well. The method really has been working great for us and you are welcome to use it. Who knows, you may even find a load that will shoot the shots into the same hole. ;)
Hope this helps.