Thanks Pete;
DuPont MX, Oval & Bulk Shotgun were still listed in a 1950 Lyman manual. Bulk is listed as suitable for 3-3½ dram measures with from 1-1¼oz of shot. MX is given only in a 3 DE loading (25.5 grains) for 1-1¼oz of shot, while Oval is recommended "Only" for a "Max" load of 40 grains with 1¼oz shot. It was noted in the Rifleman article that this 3 DE loading of Oval was in fact an "Underload" for that powder. It is noted from the charts that while this powder did give the lowest peak pressure it also had a quite high pressure at around the 4" point. It is well to note that these test were run with all of the powders being loaded to give essentially identical ballistics to the same wt of shot. This was seemingly done to provide a showing of the requisite presure curves developed & not a blanket recommendition of the loads. The load of Ballistite was certainly pushing the envelope from one end while that load of Oval was one which would have been subject to failure under many field conditions, especially for the cold weather use it would have been most apt to be used in, as a waterfowling load. The Lyman manual recommended against its use for anything other than obtaining maximum velocity with the 1¼oz shot load (12ga).
I am still a firm believer in using powders under shot loads for which they were designed, keeping presures reasonable by limiting the total balistics of the load, & forgetting all these "Super Low" pressures using loads for which the powders were not designed.
