I have loaded probably 1000 308's and probalbly 100 7mm-08 in the past without issue. Always get2 or so with little runout. Any other ideas? I set the seater up just like I always have, touch the shell mouth and back up 1 complete turn.
buy a new shell holder[:-]
J/k sounds like it has to be seating die or sizing issue, neck out of square, or wall thickness problem, try a different batch of brass would be my first idea if possible
, take care man
keith