If you have a LabRadar, then I would shoot 3 shots per charge weight on paper and record all velocities to get a bigger picture of how the load combination is working.
When I refine, I will choose the middle load typically then do seating depth. I have done seating depth testing before powder charge and after powder charge and it seems to work either way. If you do seating depth first, start at your starting load and go from .010 off the lands to .050 off in .005 steps. If your magazine won't allow you to get that close to the lands, then start .020 short of the magazine and work back from there. If you do seating depth first, it can make the powder charge testing easier to read with smaller groups. I like to find a good seating depth while the barrel is still fresh and before I do any real load development. Then I will refine the seating depth after I find my powder charge. You can still do the powder test with all the bullets .010 off and then test seating depth afterwards.
