@ 03:51 am (GMT)
Martin TaylorThomas offered some good advice in looking at some of the old threads, much of this has been worked through to its conclusion withy great info offered.
Seating to the lands is a folly in the 308w, totally unnecessary to achieve sub moa accuracy! 308's use jump to gain velocity as do many sammi spec cartridges.
Address the rifle as per your book & Nathan has said, start at the heart of the problem. As we discuss on here, Harmonics can be a real pain in the ass, so minimise their effects.
Long for calibre vld's struggle in most calibre mag lengths and you will find better performing options for game without to much trouble that will feed. The ultra high bc's just are overrated unless your pushing things way, way out & beyond its effective range for game anyway.
Please don't take this as preaching, it's just the steps that we have all been through using Nathans info. Unless you have a real brumby, the Howa will give reliable accuracy once you sort things out with multiple weights.