If I remember correctly the Hawks go 25 BHN. Seems I remember reading that they are annealed dead soft. If I didn't cast they would see use in all my old rifles.
I'm pretty sure there was a picture of at least one German double in that article. I didn't recall the author's name but I expect you're right. I did enjoy it because you just don't see much written on the 43 Mauser. It's really a good ol' cartridge once a person gets it shooting accurately....which can make for pulled hair and profane language.