A shot pattern of a smaller diameter will show up better in a photographic setting than will a larger diameter pattern. The accuracy of the shot string dimension in the article would depend on how the figures were arrived at. If photography was used, the quality of the camera equipment could determine the accuracy of the results. Brister knew how fast the car was moving and where the shot started and stopped. That would result in accurate empirical research results. I'll have to reread Brister to review exactly what conclusion he reached and how.
