We guys who use cast bullets routinely weigh bullets for top accuracy. I'll take a batch of bullets and sort them by one standard deviation. A batch of bullets normally approximates the standard distribution that you learned about in statistics class. There's a good article explaining the process
under this link.
Several years ago I bought a batch of blemished HPBT bullets and I've also sorted them by weight. I was astonished to get almost three grains between the lightest and heaviest bullets, so I put like weights in small zipper bags and load them in batches with like weights.
Weighing bullets is not unheard of.