I am not a benchrest shooter.

I quit weighing every charge some time ago. I really don't think it is the biggest factor - seems like I've seen a list somewhere of biggest factors for accuracy. Sizing a straight, consistent piece of brass is where all the concentricity starts. My guess is that if a piece of brass weighs different from the mean, perhaps it is thicker on one side than the other and out of round.

I

“Always do sober what you said you'd do drunk. That will teach you to keep your mouth shut.”
― Ernest Hemingway