Yes Gunner,it is made from .404 Jeffery brass.
Ed,you mean necked up (to .458) and shortened .404 Jeffery case,not necked down. A .458" is bigger than the .423" that what the .404 Jeffery bore diameter is.
Listen to what I mean, not what I said, dammit!
Yes...necked up to 0.458" and shortened. I was thinking about the .375 and .416 versions when I typed that... Fingers went faster than my brain, which isn't too hard some days.
Did it on another thread a couple of weeks ago. My keyboard allowed me to seat CCI LR primers in .223 brass... One keystroke and it was done!
Ed