I was doing some load development recently and having decided on a charge weight I tried experimenting with the seating depth. While I was at it I thought i’d try some neck sized brass vs some FL sized brass. It tried two depths in both sized brass types, everything else was identical. The neck sized brass shot better in both depths. So I have just loaded up some more of both types in my preferred depth and I decided to check the concentricity. The fl sized stuff was +or- 5 thou out, giving a wobble of 10 thou, the neck sized stuff was +or- 1 thou out, giving a wobble of 2 thou. The fl die is a RCBS and the neck die is a Lee.