>Just curious. Does anyone sort their pistol brass by headstamp so that they can make brass specific adjustments to their reloading process.
For any handgun I have, it makes no difference. If I average all the groups of mixed cases and all the groups of matching cases for the exact same bullet, powder, and charge weight and loaded at the same time, the mixed cases actually come out with a statistically insignificant smaller average group size. Most of the mixed cases were of the most obscure and mis-matched I could make them.
For rifles, it hasn't made any difference at 100 yards.
>Also, regardless if you sort or not, please let me know how many pistol rounds you reload on average in a year?
This year, probably about 2000 (I haven't felt well since Christmas). Generally, about 5-10k
>I understand that each case manufacturer is slightly different in thickness, length, etc which could mean some fine tuning adjustments to case belling, crimping, OAL, etc, but I'm curious how many take the time to go to the extent of sorting by headstamps. Especially those that are reloading 5, 10 or even 20K per year.
Again, not at all. For handguns firing straight wall cases, there is no reason to trim cases. If the case head spaces on the case mouth, any trimming of cases will only increase head space and reduce accuracy.
Some trim rimmed revolver cases to get more consistent roll crimps. I can't even see the difference in length, have never seen any difference in roll crimp, and when I tried it for my S&W M52, could find absolutely no benefit to trimmed cases—they certainly were NOT more accurate.
For bottleneck cases, they can grow with each shooting and they do require trimming.
Now, for the common sense of your questions, even though most of us have still TRIED these things:
There is a world of difference between trying to reduce a group size by 0.01-0.1" with a group that is <0.4" (where the idea "it couldn't hurt" might actually be justified) and trying to worry about such things with a handgun that is lucky if it can shoot <15" at 100 yards (maybe someone will tell me I am wrong, but a 2" group at 25 yards would appear to be 4" group at 50 yards and at least an 8" group at 100 yards and how many of us shoot 2" groups at 25 yards?).
The two shooting worlds simply have nothing in common. Remember, a good rifle can stay under 2" at 100 yards (my well-used Win M-94 .30-30 from 1952 will shoot 1.75-2.5" groups all day long at 100 yards with iron sights and my 65 year old eyes) with mixed cases and no case prep (other than to be sure the case length is safe) and your handguns aren't even CLOSE to the same level of accuracy.
As long as you stay safe, you can do all the case prep you want, but you will be much better off spending that time at the range shooting or reloading so you get back to the range.