Was wondering if there is any significance to the numbering system used on powders. As an example, we all know that the .30-06 Springfield stands for .30 caliber- developed in 1906. .257 Roberts named after it's wildcatter, 7x57 7mm bore 57mm length. Now is there any meaning to say IMR-3031? Does the 3031 have any meaning or did DuPont just grab it out of the air. I know Varget stands for Varmint/ Target and H-380 for the load in the .22-250. But what about the numbered powders. How about the new IMR-8133 or 4166. Is it something to do with the chemical formula? I know it's a crazy question, just curious. Any takers? RRM
