One of the things that often gets tossed around in these discussions is bullet selection. Aside from the fact that we can only shoot animals with one bullet at at time, unless we like to fill them really full of holes (or feel the need for a soft and a solid), bullet selection should be adequate for the purpose of the cartridge chosen.
I just looked through the latest Midway catalog, at the A-Square, Barnes, Hornady, Lapua, Nosler, Norma, Swift, Sierra, Speer and Woodleigh bullets that can be ordered in .338, .358 and 9.3mm. I broke them down into weights, without trying to further break down the types of expanding bullets, only noting those companies that made solids.
I also didn't count handgun bullets in .35. That advantage of .35's has always escaped me, since I prefer to shoot handgun bullets out of handguns, but here we are talking about big game anyway.
The leader, of course, is .338 caliber, with 34 weights of rifle bullets available from 160 to 300 grains.
There were only 18 weights of .35's, partly because two companies (the European firms of Lapua and Norma) don't make any. Weighst ranged from 180 to 310 grains.
There were 15 weights of 9.3's. Here Sierra doesn't make one. They ranged from 232 to 320 grains.
But now let's look at this a little differently. Generally we want a necked-up .30-06 because we want to shoot heavier bullets.
In .338 caliber there are 4 bullets of 270 grains and over,
but half of those are match bullets, which some hunters may or may not want to use (or might not be able to, because they're both very long 300's). There's only one solid, the 250-grain A-Square. On the other hand, everybody makes a 250-grain except Norma.
In .35 there are 2 bullets of 270 grains or more, one a solid, the 275-grain A-Square. Only 5 of the 10 companies even make a 250-grain, though A-Square makes a 275, Swift a 280, and Woodleigh a 310.
In 9.3 there are 9 bullets of over 270 grains available, including 7 286's. There are also 4 solids, all 286's except the 320 Woodleigh. Four companies also make a 250, but only one makes any bullet under 250 grains, the Norma 232 Oryx.
In general, the .338-06 gets the least velocity in any given bullet weight, by reason of it's smaller bore. On the other hand, .338 bullets also tend to have the highest BC's of any of the three diameters.
The .35 Whelen can get a little more zip out of the same bullet weights, but in the lighter weights (under 225 grains) BC is so poor that none of the bullet have any advantage for longer-range shooting.
The 9.3x62 gains about 5% over the .338-06 with the same weight bullets, and 2% over the .35 Whelen. This is both because of the extra diameter of the bullets and because the 9.3 case has a little more powder room, since the shoulder is further forward than on the .30-06 case. This doesn't show up in manual data because of the lower factory pressures, but the 9.3 will safely get 2700+ fps out of a 250-grain bullet, and 2500 fps or so out of a 286.
So if we get rational about all this, here's what we find:
1) The .338-06 is the best choice for somebody who wants to use both .30-06-weight and heavier bullets.
2) The .35 Whelen is the least versatile big game cartridge of the three, since it's lighter bullets simply don't keep up. However, handgun bullets can also be used, if that's important to you.
3) The 9.3 has a far greater selection of truly heavy bullets, but almost nothing under 250 grains. The selection of 286's is quite varied, with something in every price and performance range. It's ballistics are are also the "biggest," and there are far more solids available.
So the 3 rounds cover very similar territory, but there are differences. Somebody who really like to use really cheap bullets for practice would go for the .35 Whelen. Somebody who wants one rifle to span the widest variety of performance in North America would probably go for the .338-06. Somebody who hunts really large or dangerous game, especially in Africa, would probably go for the 9.3. But to try to prove that one is vastly superior than the other two is very much like arguing over the .270, .280 and .30-06. Most of us could hunt the rest of our lives with any of the three and not notice all that much difference.
