THE development of a practical method for producing steel cartridge cases became necessary when the critical shortage of copper made it imperative that the standard brass cases be replaced with ones made of steel.
A group of manufacturers, including Buick, worked on the problem with the Ordnance Department, and a cartridge case committee was formed, consisting of representatives from both Ordnance and industry. Very successful results have accrued from this cooperative program, and, according to latest reports, steel cartridge cases in practically all calibers will soon be in volume production.
This paper tells the story of how the process developed by the Buick engineers was accomplished, and describes the method in detail.
The Buick process has been applied successfully to the manufacture of steel cases of the 75-mm size, which are now being produced in large quantities.
Thirty-one major manufacturing operations are used in the production of these cases, the most interesting and unique ones being a series of four cold-drawing operations. These are carried out on a 750-ton double-acting press, where the cup is drawn from 6 in. to 15 in., and to the approximate form of the finished case, there being no substantial change in the diameter during the draw.