You may have an underlying issue (like the uneven stock contact with the barrel you mentioned in the gunsmithing forum) that is frustrating your load development efforts. If you are getting 1 moa of error due to the stock issue, then beyond a point, improvements you make to your loads may be largely masked by it.
I think from your comments that you may misunderstood Newberry’s idea. Properly applied, his system works extremely well and is, IMHO, a better alternative to the Creighton Audette Ladder used in past decades. It is based on the observation that some loads of some component combinations, like the Federal .308 GMM with 168 grain SMK, exist that work well in a broad range of rifles and barrel lengths. It then provides a method for systematically identifying such loads, but it does not suggest you will find such a load in every component combination you try, no matter how accurately they may shoot at some particular sweet spot in some particular rifle. Indeed, the OCW loads are exceptions rather than the rule. His recipe list is based on a number of people with a variety of rifles all reporting good precision with the same load.
In addition, his round robin technique can also identify sweet spots with loads that are not good OCW candidates. They just won’t have the wider charge weight range OCW load does.
(A note of caution with the load recipes on Newberry’s site: they all use Winchester cases, exclusively. Winchester .308 cases are a design that was developed to have extra powder capacity for the 1992 Palma Match. It is about 15 grains lighter than most other commercial .308 cases and about 30 grains lighter than the heaviest military cases (IMI in my measuring). This means a load developed in a Winchester case would need to be knocked down about a grain in most other brands of commercial brass, and down by as much as two grains in some military brass to keep pressure and barrel times close to the same as they were in the Winchester.)
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