This is true. You can get heavier bullets for the 9.3 and there is a larger variety to choose from. This has been one of the most popular calibers in Europe and over there everybody makes it.

I used to have a Rem 700 Classic in 350 Rem Mag. It was a good caliber but the 9.3 outshines it in every way so I sold the 350. The 350 was virtually ballistically identical the the Whelen but is was a shorter case so it could be built in a lighter rifle. Mine racked up a lot of deer and elk but since getting a 9.3 I haven't missed it at all.