if You are using a variety of brass, with each piece of brass having been loaded different numbers of times, you are probably dealing with over worked brass. This gives them almost a memory or rebound while sizing. Annealing or getting new brass and keeping consistent “workable” brass is what I had to do to solve my 3-4K variance. I know this a big of a variance as you have but I would bet it’s part of the issue. Would highly encourage to shoot the same type brass. There are a lot of inconsistencies within 100 pieces of brass from the same company produced at the same time, I can’t imagine a random selection of brass.

Thanks hunterturf

I don’t know yet from experience but I have purchased some competition seating dies hope this will help with inconsistent seating depths looks like just looking at how they work it will have to be dead on with the micrometer reloading is learning process you probably want ever master

No. Micrometer just allows you to make precise adjustments. The seating stem and how well it matches the point of the bullet you are using makes a big difference. For some dies, you have to buy a special seating stem for VLD bullets.