Thanks to all that replied!Use a scale to set your loads. Assuming you know the amount of powder you want to throw, pick a bushing see if it throws close to the desired weight. Use the numbers on the bushings to pick one that will throw more powder or less. If you find a bushing number that throws your desired powder weight, write it down somewhere to use as a starting point next time. If you were to build your own chart for Promo with your bushings or even if someone has one to give you, it will likely change the next time you get another lot of Promo. Even the MEC bushing chart should be double checked with your scale. You'll soon find a range of bushing numbers that you use, but always weigh a few charges to be sure. Good luck.
They must have an awesome leak in their system if they are able to sweep up that much powder.Promo = the stuff that gets sweeped off the floor and mixes to a burn rate that equals Promo. BY WEIGHT. So... it varies by lot, and you need a scale to get an accurate WEIGHT from whatever bushing.