Darmo said:
When sorting round balls by weight how much difference in weight do you use
I use Dutch's system. My criteria for discarding a ball is if it is more than 1 grain lighter than the heaviest ball. This assumes that the lead alloy that you are using is consistent and you are not introducing a difference in weight due to a change in alloys. I would not worry about sorting them any closer than one grain lighter than the heaviest ball.
The reason for using the heaviest ball as your standard is that as long as the alloy is consistent, the only reason for a ball to be any lighter than the heaviest ball is that it contains a void causing it to be lighter. The heaviest ball contains no voids. I wouldn't worry about weighing any closer than 1 grain because it is highly unlikely that you are good enough of a shot to tell the difference with less than 1 grain variation. Many of us cannot tell a change in accuracy when the ball varies by as much as 5 grains. If you don't have a copy of Dutch's Accuracy System, you owe it to yourself to get a copy.
http://blackpowderrifleaccuracy.com/
If you order a copy from him, you may have to give him time to get it to you. But, he will get a copy out to you. He is old and slow. Hell, he is so old, he remembers the day dirt was invented. :haha: