Like the powder manufacturer's have always said since I pulled my first handle doing shotgun with MEC over 50 years ago not sure what is new here?? In those days the bar was the bushing and the entire bar had to be changed imagine
Powder Bushings Charts
A reloading scale is required to check the nominal weight of a powder charge. Powder bushings can vary in the charge weight they drop and could vary as much as several grains under certain conditions. Powder density, moisture content, and loading technique can cause a variation from the bushing weights listed on the charts. Also, the loading machine vibration affects charge weights. A complete loading cycle should be completed to assure an average powder charge weight. The information in these bushing tables has been supplied by the reloading machine manufacturers and is not a reloading recommendation or a result of Alliant’s testing
What's wrong with that I still use those bars people were a lot more on the ball in those times. And the bars were $4 bucks a piece and powder cost $5 bucks a pound. Don't laugh I am OLD.