Not sure what the original progressive powder was. A couple which were pretty early on the scene was DuPont Oval & Hercules Herco. A 1950 Lyman reloaders guide lists 37 grains Herco with 1 3/8oz shot as Max DE, shell length no stated. Another Lyman's from later in the 50's gives 38 gr Herco as a 4DE-1 3/8oz load for 3" shells.
These were of course for paper cases with card & filler wadding. Likely for the premium Super-X loads felt was used for the filler rather than fiber.
Oval may have already been discontinued by 1950 as no loads are listed for it in a Lyman 1951 manual & the 1950 one only shows it for 1Ľoz loads.
Perhaps someone can come up with more positive data.
PS; These loads were in 12ga, "NOT" the 3" .410.
Last edited by 2-piper; 04/30/12 07:20 PM.
