The 30-06 round allegedly used has a 5cm casing fwiw.

And harbor freight sells handheld electric engravers which are typically used to put your name/initials on (harbor freight tbf) tool steel, so brass would be fine.

But also, pics required before I’d consider believing it. It switched from trans writing on the bullets to Internet/Reddit subculture memes pretty damn quick after the Internet erupted into bloody Kirk memes.