I finally mixed up all my Hornet brass that was by weight. I am just not accurate enough to worry about that kind of stuff any more. It is like anything else, you can get as crazy as you want getting everything 'just right'. It still comes down to the shooter in the end. I will not state for certain that most of that detail 'actually' helped, but maybe mentally? Which is a plus.
On a plate shoot (handgun, center fire) once I ran into a guy that was there to watch and after talking to him he shot my spare piece with some low power close range practice ammo I had. He ended up in 2nd over all and beat me. It was pretty fun to watch. If he had not had a 'flyer' (I warned him the ammo was not for longer distances) he probably would have won.