30 years ago, we probably all put a lot of stock in the idea of "energy transfer," myself included. The Hatcher Theory, which is what we're talking about, has simply been demonstrated as not accurate.
Recommendations on buying a press. If your budget will support it, a Dillon 650 will let you crank out ammo like nobody's business Having said that, I don't own one. My best friend and I used to reload a bunch of 45 ACP, 9mm, and 5.56. The Dillon is great for that, and he has one. But we figured out we'd rather drink whiskey, smoke cigars, and tell lies than spend THAT kind of time on reloading. Any more, for the ZA stuff, we buy factory. But for hunting ammo, we're both pretty anal, so we run lot sizes of maybe 50 at a time.
But...
I do most of my reloading on an RCBS Rockchucker. If you're going to drop coin, drop it on an automated powder dispenser. The good ones will run $300+. Bottom line - if you're reloading for the Zombie Apocalypse, get a Dillon. If you're reloading because you want to create consistent hunting ammo, get a Rockchucker and an automated powder dispenser. The powder dispenser will cut your reloading time by at least half. Still not as fast as a Dillon, but for hunting ammo, it isn't like you need to make ammo by the case.
While some folks say recoil from a 9.3x62 is mild, that's relative. It's mild compared to any of the .416s or bigger, but it still thumps like a 338 WM. I've shot as many as 40 in a single session, and that was too much by about 15 or 20. I'm a big guy, 6'6" and 240#, and not recoil sensitive. But 9.3 is still a thumper.