As I see it, the big problem with weighing .22 ammo is that you can just weigh the entire cartridge, not the components. Because the bullet is by far the heaviest component, a small variation in its weight might not mean much, while the same weight difference in the powder charge might have a significant effect. There is no way to know where the variation is coming from in an individual cartridge, or whether it is significant.
Rim thickness is measurable, but I'm not convinced it's worth measuring and sorting. I'm not made of money, so I invest in ammo depending on what I'm trying to accomplish. Plinking is plinking, offhand doesn't require precise ammo, at least not the way I shoot, and even regular club benchrest matches aren't worth $20 per box ammo, so I shoot mid grade stuff. A major championship is something else, so I might splurge on a few boxes of Eley Tenex. The main thing you're paying for in higher grade ammo is consistency.
Paul
