Okay, with the various opinions expressed in the thread about weight sorting, I think I have the grounds for a small experiment. Please let me know if you think this will give some insight. Aside from the small sample size, I don't see anything obviously wrong with it. I will use 60 rounds, divided into 3 groups of 20. All 60 will use Remington number 6 1/2 primers. All will use Varget for the powder, trickled and not thrown to make the exact same amount of powder in each case. All will use the 69 grain Sierra Matchking .223 bullet. The three groups of 20 cases each will all be the same PMC headstamp. I sorted out the ones with the large headstamp from the small, and these are all small. One group will be unsorted. The second group will be brass that weighed in at 93.2 grains +/- 0.1 grain. The third group will the be the brass that was on the two extremes of my recent sorting of 212 cases. There were just 3 cases that fill into the 91.8 range, 7 in the 92.0 range, 11 at 93.6, and 5 at 93.8. I'll use 10 from the light groups and 10 from the heavy groups mixed together. Of the remaining cases the biggest group was 93.2 grains, with 44 cases, so that was chosen for the second group mentioned above. All the cases were run through the same sizing die, all were swaged to get rid of the crimp if needed, all were trimmed, chamfered, deburred, and had the primer pockets cleaned with the same tool. I'd like to claim they were all once fired but that is not the case. Some are, some aren't, and there is likely a mix in each experimental group. I will put 20 rounds into each of 3 identical targets from 100 yards. The rounds will be loaded into a 20 round mag 5 at a time. I will shoot 5 from one group, then 5 from the next, and so on in rotation until all 60 rounds are fired. Any buildup of fouling or heating of the gun and so on will be distributed over all three groups. I'll take my time and use a solid front and rear rest for all shooting. Again, the sample size could be larger, but I hope this will give some idea if weight grouping is worth the trouble. What do you think of the protocol?