I posted this as part of a discussion on the medium bore forum but thought it may get some interest over here too.

Funny how what you think you have can have a little twist to it...
What I thought were 300 Hoffman cartridges in Hoffman boxes are actually .270 wildcats based on Hoffman brass.
I thought the bullets looked a little small for a .30 but never measured them and didn't notice the writing on the bottom of the box.
I don't know what the modern equivalent of this cartridge is, but it looks like it would be swell. My guess is that they were loaded up in the '60s but not sure. The brass is 2-9/16"

With today's premium bullets in a long enough magazine and deep throated rifle it would be great in the lower 48 and as a plains rifle. roger