Comments on the process of weighing cases. Have been doing this for a while. Am retired, so I do this because I can.
What I have learned/observed so far:
There is a huge difference in the weights of sized TTL cases, IME. Was weighing 30-06 cases for my son's rifle. A large batch of mixed brands. The most common weight was about 187 grains. The lightest was 180 grain... and the heaviest 204 grains. So there for a large difference in internal volume.
In my experience cases grouped by weights were a little more consistent at the range... in 223, 7 x 57, and 30-06.
Since I don't always know what the case weights will be, I don't decide beforehand any +/- . I group by results.
After I weigh a few of the cases to get an idea of what my weight range will be.... I get/make a long piece of lined notebook paper.
tape it to my work surface. Draw a new heavy line on that skinny blue line. then I number each blue line with the sequence of grain weights thru the range I expect to measure. Then I weigh cases on my digital scale and stand each case up on the line labeled with its weight, such as 187.6 grain.
This 'physical histogram' ends up with uneven piles.... a distribution of the case weights in the lot I have weighed.
Now I can decide how to group the cases in groups that have similar weights. The outliers you can use however you want.
Once you have done this a few times its not complicated. Save the pages you use for next time....
If you don't tape the page down... or you bump the table... some of the cases will fall over and have to be reweighed.
Doing this in the presence of your conjugal partner is sure to generate snarky comments defaming your character and intelligence.
