Acceptable run-out on .308

[Grimstod]

Have you ever tried supporting the front of the case from the middle of the shoulder?

No. You should not try to either. Shoulder does not suport the case. It only controles headspacing.

 

[T-shooter]

No. You should not try to either. Shoulder does not suport the case. It only controles headspacing.

I tried, too hard to do. I run the case headspace at .001". The cases after resizing are not as close as I could like. I use a modified Forster benchhrest full length die. The necks are way too small to support the front of the case in my stock barreled rifle. I check a couple fired Lapua cases years ago and found these dimensions after full length resizing. I do use the expander ball but the shaft floats and does not pull the necks out of alignment and it's sized for .002" interference in the necks. So maybe a ballpart .00075" per side on the front of the case.