7X47 for IHMSA That was before everybody who wanted one had a chrony.
I bought a chrony then, but it didn't work.
I would believe whatever the books say about 7mm TCU.
This is from Handloads.com
130gr SP 28.0 gr AAC 2460 2,100 fps from a 14" TCIf there were a 7mm TCU Handi Barrel I would want
it rimmed the way earl says.
Back to the 300 rimmed.
The pictures show the case about the same length as the shoulder on the 223.
That will be too long for 357mag brass, but the Max brass should be good.
Quick says 35mm
35mm = about 1.38 in
more than mag and less than max