Most of us at one time or another have run into those steel cased .45ACP rounds from WW II. Know the story of them? Sort of interesting, to me, anyway.
During WW II the fate of South America was in question as to which way it would lean politically. If the South American nations aligned with the Axis Powers, the copper supply to the United States would be greatly curtailed. Iton was plentiful, and steel for cartridge cases was an option. This was before useful stainless steel were available.
Chrysler Corporation, operating the Evansville Ordnance Plant under contract, undertook the task of finding a way to prevent the steel from corroding. The came up with a phosphate coating that worked.
The .45 was the ideal round to experiment with, and before long these rounds were running off the line. They bore the H/S of "EC" for Evansville Chrysler, and the date of 42 or 43. When more cases were needed, the Sunbeam plant began producing cases, and are stamped "ECS" for Sunbeam made cases.
They later put out a news release entitled "Bullets by the Billion." By the end of 1943, things stabilized and brass cases once again were back into the supply line.