For over two decades from the late 1890s to the early 1920s, the heaviest American factory loaded smokeless powder 12-gauge shells were put up with 3 1/2 drams of bulk smokeless, such as Hazard, New Schultze, DuPont, E.C. No. 1, New E.C., Alarm, Dead Shot, Oriental, New Troisdorf, and Empire; or the equivalent in dense smokeless powders, such as 28-grains of Ballistite, 28-grains of Laflin & Rand Infallible, or 38-grains of Shotgun Rifleite; and 1 1/4 ounces of shot. These could be put up in 2 3/4, 2 7/8 or 3-inch shells, and with bulk even 3 1/4 inch shells, but these longer shells only had more and better wadding, not a heavier payload. In the early 1920s, the ammunition companies, led by Western Cartridge Co. with their Super-X loads, began using progressive burning smokeless powders. Western literature of the period discusses a proprietary powder of their own, and also Du Pont Oval.
The A.H. Fox Gun Co. Super-Fox brochures from 1923 and 1925 discuss shells loaded with DuPont DeLuxe and DuPont 93?
I have been wondering about the pressures of those old shells from before the days of progressive burning smokeless powders for some time. From the late 1890s to the early 1920s, the heaviest factory loaded 12-gauge 2 3/4 inch and longer shells were loaded with 3 1/2 drams of bulk smokeless powder or some number of grains of dense smokeless powder (28 grains of Ballistite was one of the most popular) and 1 1/4 ounces of shot. In several of the old sporting books I've read the authors expressed the opinion that these loads were excessive and were of the opinion that the 3 1/4 dram 1 1/4 ounce was a better balanced load.
I've now scored some old DuPont Smokeless Shotgun Powders books from the late 1920s and early 1930s. These booklets are very lengthy tomes, 96 and 103 pages, promoting their DuPont Oval progressive burning powder, which allowed the development of the high velocity loads like Western's Super-X, Remington's Nitro Express, etc. In the manual they show a table giving the pressure of the 3 1/2 drams DuPont Bulk Smokeless pushing 1 1/4 ounces of #6 shot as 11,700 pounds, with 3 1/2 drams of Schultze 11,800 pounds, and the same load pushed by 28-grains of Ballistite at 12,600 pounds!! Velocities were all given over 40 yards, not the muzzle velocity figures we are use to seeing today. The DuPont bulk gave 943 fps, the Schultze gave 941 fps, and the Ballistite 966 fps. Meanwhile 40 grains of their DuPont Oval gave that 1 1/4 ounce of #6 shot a velocity of 981 fps with a pressure of only 9,400 pounds.
