Been awhile since I did my experiement of loading 4 or 5 sets of 3 rounds each and only difference in my reloads for my most accurate rifle, a Ruger that I'd rebarreled to 7x57, was the primer used. I used: CCI magnum, CCI BR, Wolf standard LR, Magtech standard LR, ....may have used either Winchester or Remington standard LR too in my experiement
When I'd finished shooting all my sets of reloads at a 100 yard target, had about a 5/8"" wide hole that was about 2 1/2" long. In other words a vertical string of hits on my target.
As I recall, the CCI magnum primer hit highest on the target, rest of sets each grouped at points lower on target. Just a guess on my part, but point of impact on target about 1/2" or so between each group.