England had the same problem
1896 UK Rules of Proof Service Charges for Nitro Powder
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA7 
After WWI, the standard for 2 1/2 shells became 1 1/16 oz. with 42 grains (Old) Schultze Bulk (3 Dram), 36 grains E.C. No. 2 (Improved) or 33 grains Imperial Chemical Industries (Eley & Kynoch Cartridges) Smokeless Diamond powder.
DuPont purchased Laflin & Rand in 1902, and American E.C. & Schultze Powder Company in 1903. New E.C. Improved and New Schultze were introduced in 1906 as DuPont products.
Hazard Blue Ribbon Bulk Smokeless was listed as a DuPont product in 1908.
In 1912 under the Sherman Antitrust Act, Laflin & Rand was dissolved and DuPont was split into DuPont Powder Co. (later DuPont American Industries), Hercules Powder Co. (which retained Infallible, E.C. and Schultze) and Atlas Powder Co. L&R Orange Extra black powder was still offered in the 1927 Hercules Sporting Powders booklet.
An attempt to bring order to U.S. smokeless powder chaos
Simplified Practice Recommendation, Loader Paper Shot Shells, U.S. Dept. of Commerce, Bureau of Standards, Jan. 1, 1922 -
https://play.google.com/store/books/details?id=oSwXAQAAIAAJ 
