Powder burn rate

fiver

Well-Known Member
Ric beat me to it.
St. Marks is pretty much the ball powder producer for the planet.
here's a little run down.

The United States military replaced black powder during the first decade of the 20th century with smokeless powders formulated from nitrocellulose colloided with ether and alcohol.[2] 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.[3]

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.[4] 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.[5][6]

This manufacturing process also worked with newly manufactured nitrocellulose. Manufacturing time was reduced from approximately two weeks for extruded propellants to 40 hours for ball propellants.[7] Rate of burning is controlled by deterrent coatings eliminating precision forming and cutting machines required for surface area control of extruded propellants.[8] Safety was improved by performing most of the manufacturing process in water.[9] Olin subsidiaries began manufacturing ball powder specification WC846 for .303 British ammunition during World War II. Hodgdon Powder Company salvaged 80 tons of WC846 propellant from disassembled .303 British military rifle cartridges in 1949 and sold the propellant to handloading civilians as BL type C. The C was to indicate the propellant burned "cooler" than traditional Improved Military Rifle propellants. Olin continued manufacturing WC846 for both civilian ammunition and 7.62×51mm NATO cartridges[10] after the war.[11] Manufacturing operations moved in 1969 from East Alton, Illinois, to the St. Marks Powder plant in Crawfordville, Florida.[12]
 

fiver

Well-Known Member
the weird thing is with the speed and simplicity of making the ball powder, as well as the ability to tune the burn speed simply by modifying the process and not the recipe so much you'd think the stuff would be half price.
 

Ian

Notorious member
Universal also got moved to Canada and turned from green to purple. Still good stuff.

+1 on Speer load data, Ric, my old trusty #11 that was the latest edition when I began handloading was my starting point for heavy bullet loads. Keep the internal volume, primer brand (CCI, duh), and bullet weight close to tested data and you're reasonably close to tested pressure.