Have seen different dram load chart for gauges and weight of shot.
12ga 3 dr 1 1/8 , 12ga 3 dram 1 1/4.... same with other gauges and weights with velocitys. I believe Dr. Hause and researcher were in that old thread maybe they will come along and link us.

Kinda weird though since several different black powders back when they used the dram thing,

Great question! Love to see explication again