Lake City Steel Cased M1 Carbine Ammo?

Hi

I just read a book on how Lake City retooled to make steel M1 and .45ACP during WW2.. some real pioneering work!

It was done because of a concern that there would be a shortage of copper...

Found a full box of Lake City carbine ammo w/ steel cases. Head stamp is LC 54. Box is marked Lake City Arsenal and lot # LC S 13864. Both cases and bullets are attracted to the magnet. Cases have a funny look to them, like zinc plated?

LC did make steel cased ammo in the mid 50's on a limited basis. More experimenting then anything else testing different powders and types of steel but they gave it up as the same problems from WW2 were still there in the mid 50's.