While it is true we will use one brand of brass for a special test, special SD ammo, or competition rounds it is not customary to sort brass by weight. It really won't get you anywhere. I'd be content to sort by brand only, but I don't even do that for plinking.
Really, the only thing you've proved by this exercise is: > Don't weigh finished cartridges trying to determine if you left the powder out of any of them. < There is more variation in the brass than any other component.
If you want to sort for critical testing, then measure the volume of water each will hold, because it's the volume under the bullet that makes the most difference. But as has been said, in pistol it really won't be worth you effort.
On another note... What are you plans for a press ? Have you been buying components, because there are really excellent deals out there right now ? I've got a line on a Dillon Square Deal and a Hornady LNL AP with case feeder.