This is a normal 45ACP cartridge with steel case made by
the Evansville-Chrysler Plant in 1942.
I copied the correct link, so you can see the pictures
Thanks René. I had myself and a couple of friends scratching their head over this one. I had just put a micrometer on it when I saw your message. Saved me a lot of work.
There is web copy of “Bullets by the Billion” here: imperialclub.org/Yr/1945/46Ammo/Cover.htm
It tells the story of the manufacture of steel-cased .45 and .30 Carbine ammunition by Chrysler during WWII.
Great! I’ll pass it on to my friends as well.