That post script was written in the day of few people having chronographs, I think. Comparing a good bullet, say, in the 9.3x64 against a virtually identical speed and energy, but poorly designed bullet in the .375 would give false results, hence the text presented. To compare, the bullets should be of similar construction, as good bullets are available in all calibres today.

I think those two are as peas in a pod. Given identically designed bullets the results must be identical.

So - enough logic - I looked up data for the 9.3x64 myself - I see handloads listed by Vihtavuori 1st Edition as:
maximum loading: 258gr. HMK 2,670fps
---------------- 285gr. TMR 2,530fps
---------------- 293gr. TUG 2,550fps

I also looked up this books .375H&H loads
maximum loading: 235gr. Speer -- 2,900fps
---------------- 270gr. Hornady- 2,790fps
---------------- 300gr. Hornady- 2,560fps

Most other manuals will show similar results, but some also show up to another 100 higher speeds for the .375. But does that put it well above the 9.3x64? At that level of 'power' would there be any "notable" or "visible" effect - I doubt it.

I fail to see anything that would lead me to believe the 9.3 is more powerful than the .375.

Even my 22" bl. 9.3x62 makes 2,520fps with 285gr. Grand Slams. Yes - that is powerful, but from a 9.3x62, not a 64mm. The pressures are higher - so what? Little finger bolt lift. So much for the enormous power of the 9.3x64 - as loaded. Certainly one should be able to modernize it with modern powders, but more so than the .375H&H? - I doubt that or at least not enough to make a difference to the animal.

The late Finn Agaarrd once noted he'd seen absolutely no difference on African game between the .375H&H and the 9.3x62 factory loads. He went on to list other similar rounds as in the various 8mm's, .30's and the .300 mags. as producing similar if not identical results on the same game to each other.

In the 9.3 vs .375 results, he was referring to the current factory ammo, ie: 270's at 2,740fps and 300's at 2,560fps with the 9.3's factory fodder of 285gr. at 2,330fps.

Fast forward to the actual data for the 93x64 vs the .375 and I cannot see how virtually identical speeds with the same SD bullets can produce different results and we all know, with today's premium bullets, SD is NOT what determines damage and penetration, but construction sure does.

As for the 9.3x57 goes, mine (now my bro's) puts out 286gr. Norma and 293gr. TUGs at 2,200fps and 270's at 2,300fps. It even does 2,175fps with 300's and I'm sure I could get those up around 2250fps without pushing it. It is not even breathing hard with less than .0005 (5-tenthousandths) expansion at the web (in one spot only) from FL sized. I could raise it's speed another 50fps maybe even 100fps quite easily, but why bother? It shoots through moose and bears as it is.

Years ago, the 9.3x62 factory ammo ran 2,175fps with 285gr. solids and softs and was one of the very best rounds for Africa- according to John Taylor. In 1923, the ballistics were upped to 2,330fps with the same bullets and Taylor said they needn't have done that, it worked just fine as it was.

Hmmmmm - 9.3x62 at 2,175fps with a 285gr.- sounds fairly similar to my 'little' 9.3x57, doesn't it?

What's Best? What's needed for a specific purpose might decide which is best to that person, in that situation.

There are bound to be a multitude of different opinions.

It's all interesting.