@ 09:36 pm (GMT)
Nathan FosterHi Jaspur, this may simply be a case of your COAL being wrong. You are cuurently set too long and concentricty will be very poor.
Set COAL to 71mm, then rework up loads.
See COAL article in the rifle accuracy section of this site for more info as to why your COAL was wrong at 1 thou jump in the .308.
There should be another thread here somewhere close which covers the same info and also powder charges.
Bedding may need addressing, plus other factors as described in my last book (Accurizing).
Stick with it, you will get there.
All the best.