http://www.fieldandstream.com/blogs/the-gun-nuts/dangerous-game-rifles-the-roaring-forties
by David Petzal..
Petzal is the Rifles editor for Field & Stream. His writing ability and knowledge of firearms are often referred to as "godlike."

The question of the .40-calibers came up, and I feel compelled to put in my oar, as the British say. I’m all for them. What follows is a short summary of some the high points of the .40s.

When I began hunting Africa in the 1970s, if you talked to any of the old-time PHs about the best dangerous-game cartridges around, there were two that would almost certainly be on the list. One was the .470 Nitro Express, and the other was the .416 Rigby. The former was strictly a double-rifle proposition, but the .416 was for bolt-actions. Brought out by John Rigby in 1911, it is a startlingly modern case (albeit a very big one) with very little body taper and a sharp shoulder. It fires a 400-grain bullet at 2,400 fps, which gives it considerably more authority than the .375 H&H, and a lot less recoil than the .45-and-bigger rounds. Indeed, this is the great strength of all the .40s.

What Rigby also managed to do was get Kynoch, who made a great many lousy bullets at the time, to make a solid and a soft point that were very good, particularly the solid. Here at last was a dangerous-game slug that would not break up on impact.

But Rigby bolt-actions were still expensive, and required an extra-large action. For a long time if you wanted a .416 Rigby built, you had to get a P17 Enfield and open it up, or pay a small fortune for a Brevex bolt-action.

The .404 Jeffrey (it takes .423 bullets) appeared two years before the Rigby, and is sort of the workingman’s .40. I mention it here because it was at one time hugely popular, nearly died for no good reason, and is now enjoying something of a renaissance. (I think the reason the .404 went into decline was lack of glamor. It was issued to game departments, and Harry Selby [on whom Peter Mackenzie of Something of Value was modeled] used a Rigby, so the unfortunate Jeffrey round had no cachet at all.)

The original loading was 400 grains at 2,100 fps, but now the numbers are 400 at 2,300. It packs just a bit less punch than the .416, but is small enough to work through a standard bolt action, and kicks noticeably less. If you’re looking to go one step above the .375 H&H in power, this is a very good place to go.

The .416 Remington was part of the Great .40-Caliber Rebirth of the late 1980s, and is my favorite of the lot. It’s the 8mm Remington Magnum necked up to .41, and fires 400-grain bullets at 2,400 fps. It fits through a standard-length action, and is, for all intents and purposes, a more practical version of the .416 Rigby.

I’ve heard complaints about high pressures in the .416 Remington, but have shot it far more than was good for me, with both handloads and and factory, and never had the slightest problem. And I can tell you that it absolutely pounds stuff.

Last on the list is the .416 Weatherby, class of 1989. I have no experience with it, but Layne Simpson, a gun writer of the highest moral and literary worth, has. Layne says that if you want to see something large and tough knocked absolutely flat, there’s nothing like a .416 Weatherby. It fires 400-grain bullets at 2,600 fps, courtesy of a fearful powder charge. Layne reports that you can’t shoot the rifle without the factory-issue muzzle brake, and if you do use the brake, you also have to use headphones. All that power does not come without a price.

The .375 H&H is more versatile than the .40s, but lacks power for the really big stuff. The .45-plus cartridges hit harder, but they also kick a lot more. In the view of this grizzled, embittered old observer, the .40s are the way to go for a dangerous-game cartridge.
D