@Barrel Nut
When I tested primer weights, it was over multiple days in one time frame. It was basically obvious on almost every target; meaning when unsorted, groups were predominantly larger, more vertical, more ES, and more spread out. Opposed to sorted, where the groups were predominantly smaller, less vertical, lower ES, and tighter in spread.
Then when conducting refined tests from within my weight sorted qualifications, fired outliers from both ends of the qualifications simultaneously as 1 group at one aim point. They had poor overlap and clustered fairly distinctively vertically from one another.
Tested 3 separate Lot's and had difference between them as to the amount of weight extremes. Even the best Lot that had the least variance in weights, yielded the same indifference in the testing, just not as extreme since the weights were not as extreme.
My testing was done at 1000 yards, with the comp rifles and rests setups that I use at matches. Would never consider clamping the rifles into a "gun vise", for that would also change the rifles harmonics, POI, and accuracy capability. Besides, my tests need to be relevant to my rifles, rest setups, and reloading practices.
Edit in:
When I first suspected primers to be possibly effecting my accuracy levels, I weighed some and was surprised at the percentage of weight indifference to that Lot. I then had a conversation with Matt (
@dkhunt14) to what I was seeing, and it was on Matt's advise that I should look into it closer. That was several years ago now, but will always be Thankful to Matt for his insight and sharing his wealth of knowledge with me (which he does on almost a daily bases with everyone here, that reads his inputs and smart enough to listen).
Donovan