In precision reloading, this is a step that helps some people get noticeably tighter groups. This is not a process to bother with if you are reloading 9mm for a 3 Gun competition. The pistol targets are almost never more than 25 yards away and some slight variance of bullet length or weight is not going to make a significant impact difference at those distances. If you are doing reloading for 300+ yards and your sport worries about 10ths of an inch in group size, bullet sorting might be in your future.
The way I sort is a two step process. I first sort by weight. Using a very precise electronic scale, I individually measure about fifty bullets to see what the variance is and how many plastic containers I need to use for sorting. Some manufactures have very tight tolerances and weights will be quite similar. Other companies, are willing to accept a significant deviation as long as the fat part of the bell curve is near nominal weight.
We will use 6.5 Creedmoor as the cartridge. Let’s use a plastic tipped 147 gr projectile as the theoretical test bullet. After running 50 bullets over the scale, we find the low weight as 145.8 gr and the high of 148.5 gr. If 80% of the bullets are within half a grain of nominal, you are doing awesome, but let’s say the sample sorts like this.
50 round sample 1000 round run
– 145.8 0 0
145.8 — 146.2 1 12
146.3 — 146.7 8 156
146.8 – 147.2 32 692
147.3 – 147.7 6 127
147.8 – 148.1 0 6
+ 148.1 1 7
My process would be to set up seven bins. One, just in case a projectile was lower than 145.8 gr. Then proceed to weigh each bullet and place it in the correct bin. This is a time consuming process, but it will make a difference in velocity, BC and even spin mechanics; depending on why the weight is different. In this example, at the end of sorting 300-1000 bullets, you will have batches of bullets that are no more than half a grain apart. These batches should remain separated and get loaded together.
In the above example, I would relegate the three extreme outliers to fouling and sight confirmation shots. I mark them as such with a sharpie. If the distribution did not hold out at those percentages, then another choice might be appropriate. In an example with a copper jacketed tip, after sorting for size, meplat trimming might help as well.
