Regarding Ads, maybe that the heavy 7mm exceeded the mid weight for caliber 375 300, however if we are looking at SD as. Performance criteria, the the 220 30 cal end nose beats then both, at .330
Obviously 7mm heavies work, just like 160 6.5 a and 400. .416s etc.
Not so sure there is an argument to be made.
The biggest benefit of small calibers in the era you mention was improved performance over the British express cartridges of the day, light for caliber fairly fast 400 + diameter rounds.
The gain of full jacketed RN and tough softs in small and mid bores was construction first, the SD then velocity.
There really is a reason for caliber minimums in Africa. There ought to be a penetration min as well.
Ads =SD
end nose= round nose.
Autocorrect....