The 9.3X64 is an outstanding cartridge badly crippled by the lack of good quality inexpensive brass.

To say it's equal to a 375H&H is indeed high praise, but you can buy 375 at Wal-Mart (At least you can in Wyoming)and even small shops in Wyoming and Montana, have it. I was in S. Carolina a few years back and in a mid-sized gun shop I found empty brass and loaded ammo on the shelves despite the fact there are no game animals in S. C. that I know of that are the type of game usually shot with a 375H&H.

The 9.3X64 does what the 375 will do but the other side of the argument is that the 375H&H will do what the 9.3X64 will do, with the 375 being quite common and the 9.3X64 being made to be a far harder cartridge to obtain.
Too bad too. The belt-less design and ease of fitting it to most actions give it a very good set of qualities. But the industry seems to be set against it.

The same was true of the 9.3X62 form most of my life. Not very long ago, most American hunters had never heard of a 9.3X62. Now in Wyoming, Montana and some of Idaho and Utah the 9.3X62 is getting super popular. I have been doing re-barrel jons to that caliber like it's a run on the banks for the last 2-1/2 years and it was odd in that no American gun makes is offering the rifles as a standard item,yet American seem to suddenly "wok up" to the shell and there has been a huge demand for them around here.

Even if the 9.3X64 was to be offered by Ruger, Savage, Mossberg, Remington and Winchester all at the same time and Federal, Winchester Hornady and Remington all started making ammo, I doubt the 9.3X64 will ever outsell the 375H&H. It could be equal in sales, but I don't think it will pass the 375.

The 9.3X62 on the other hand is a bit less powerful and kicks a bit less too, hold more ammo in the same size magazine and get by with a bit less barrel length, yet it kills game REALLY well. So if the big companies wanted to get higher numbers of sales, I think the 9,3X62 would become the bigger seller.