I think the big point missed by the author of the article is the fact that all those pre Vietnam war era rifles being used in the photos have barrels locked into stocks with bands and hand guards. The barrel harmonics/vibration is different than a more modern free/semifree floated barrel...So different shooting technique is called for.
In my not so extensive experience shooting lt.wt. rifles I've found that pulling the butt stock into the shoulder pocket snugly with the shooting hand, looping up in a sling(if you're so inclined)..and that consistency thing that M77 mentioned helps a lot.
