Spherical powder

Ball propellant is a form of nitrocellulose used in small arms cartridges. It has been trademarked as Ball Powder by Olin Corporation and marketed as spherical powder by Hodgdon Powder Company. Ball propellant can be manufactured more rapidly with greater safety and lesser expense than extruded propellants. Ball propellant was first used to load military small arms cartridges during World War II and has been manufactured for sale to handloading civilians since 1960.

The United States military replaced gunpowder during the first decade of the 20th century with smokeless powders formulated from nitrocellulose colloided with ether and alcohol. Large quantities were manufactured for World War I and significant amounts remained unused after the war. Nitrocellulose deteriorates in storage, but military quantities of old smokeless propellant were sometimes reworked into new lots of propellants.

Through the 1920s Dr. Fred Olsen worked at Picatinny Arsenal experimenting with ways to salvage tons of cannon powder manufactured for World War I. Dr. Olsen was employed by Western Cartridge Company in 1929 and developed a process for manufacturing ball propellant by 1933. Reworked powder was dissolved in ethyl acetate containing small quantities of desired stabilizers and other additives. The resultant syrup, combined with water and surfactants, is heated and agitated in a pressurized container until the syrup forms an emulsion of small spherical globules of the desired size. Ethyl acetate distills off as pressure is slowly reduced to leave small spheres of nitrocellulose and additives. The spheres can be subsequently modified by adding nitroglycerin to increase energy, flattening between rollers to a uniform minimum dimension, coating with deterrents to retard ignition, and/or glazing with graphite to improve flow characteristics during blending.

...
Wikipedia