If I understand your post, Jeff, you're asking what US round is close in performance to the 9.3x62.
: The closest US round to the 9.3x62 is a .35 Whelen, but it's ballistics are only close to the underloaded 9.3x62 factory ammo. Handloaded, the 9.3x62 is a couple hundred fps stronger than that. The .35 Whelen Improved pretty much duplicates the 9.3x62, but, on the low side, while the .375 Whelen Improved is a bit faster with the same bullet weights, so those two Improved rounds bracket the 9.3x62. This happens when the 9.3x62 is loaded to it's best ballistics. There is no USA factory round (that I am aware of) that duplicates a properly loaded 9.3x62. It's current Sako ballistics are circa 1925.
: If you look at the measurements of the 9.3x62 - you will see a ctg. that has the dimensions of an improved .30/06 case, with the shoulder moved slightly forward and slightly shallower shoulder angle. The .375 Hawk/Scovil was originally a 9.3x62 necked up to .375, but Scovil reduced the head dimensions to that of the slightly smaller '06 for ease of making brass. Thus, he was able to drop the Hawk name. Barnes gives data on the .375 Scovil as well as a google search will bring up more data.
: Indeed, when I first bought my 9.3x62, I merely necked some older .375/06IMP brass down for the .366" bullet and they chambered perfectly.
: My currect .375/06IMP, wiht larger shoulder, has about 2 gr. more capacity than the 9.3x62, virtually the same potential - I get 2,470fps with 300gr. Bonded Hornady's, over 2,600fps with 270gr. and 2,845fps with 235's for long range deer/black bear shooting. These are maximum loads for shooting in the summer heat.