Hardly any cartridge has had so much bad press over the past couple of decades. At first, the relatively compact 458 Winchester Magnum went to Africa and performed splendidly. It compared pretty much across the board with several older British cartridges. At greater pressure in a smaller case, the belted 458 could be racked through a Winchester Model 70 to nicely handle Cape buffalo and anything else. Here was an affordable combination that put a dangerous game safari into the reach of more than just the wealthy. Just for reference, the cartridge shot (and still shoots) a 500-grain bullet out of the muzzle at about 2000 to 2100 fps. If that seems sluggish, imagine the 40-grain 22 magnum at 1900 fps. The 500 gets down the street mighty fast.
Here's the rub... Winchester obviously had their reasons for choosing to fit the 458 into a standard-length action. I suspect they did a lot of testing and were impressed with the remarkable accuracy. (It's no big job to shoot a Mickey Mouse-faced, three-shot group at 100 yards from a well-tuned rifle.) But, to achieve that approximately 5000 foot-pounds of muzzle energy of the old British cartridges, most any suitable powder had to be compressed beneath the lengthy bullet. Some powders tend to become a bit tacky in very hot weather, and the individual grains bond together like candy in a sack in similar weather. The primer needs to produce a flash that will engulf each grain of powder in fire, which it cannot do to a gummy mess. The result is an incomplete firing of the powder charge, and reduced velocity. That's probably what happened to the old, repeatedly overheated cartridges Jack Lott was using when he pissed off a Cape buffalo that day in Africa. From then on, bashing the 458 Winchester Magnum has become a sport in and of itself. The sport stops here.
I have had my share of 458 Winchester Magnums, 458 Lotts, and 460 Weatherbys. I like them all. However, for most jobs, I recommend the 458 Winchester Magnum in Winchester's remarkably underpriced and extraordinarily rugged Model 70 Safari Express. For people who prefer to hunt the Alaskan brown bear in all kinds of nasty weather, I'd suggest Remington's Custom Shop Safari KS in stainless steel. Here's where I depart from the norm…
I don't use 500-grain bullets in my hand loads of recent years. Instead, I choose the Swift 450-grain A-Frame. For powder, I have used four with excellent results: H 322, H 4895, IMR 4895, and IMR 3031. Velocities run in the 2250 to 2300 fps range. The nicely shaped Swift has a ballistic Coefficient of .325, while most 500-grain soft point bullets run under .300. The sectional density is still a very acceptable .307.
Don't get me wrong. I'm not "fed up" by all of the low-end blather about the 458 Win Mag. I kind of enjoy it; great spectator sport. I simply figure that most folks who hop on the bash wagon have no experience whatsoever with the cartridge, and this helps me to sort out the B.S. gun writers from those who have a clue. It also can help to identify those who take appropriate care of their ammunition, which does not mean to follow the example of Jack Lott. You have to have some kind of an idea as to which powder types can get sticky in bad weather, and avoid using them in compressed loads.
The 458 Winchester Magnum has been around since 1956, and will likely still be producing fine results with amazing accuracy for decades to come. Some people go to Alaska and look for the big bear with rifles that I regard to be marginal, like a 338 or 375. Imagine whatever you like in your mind. Imagine that the bear will be in this or that position, and that you'll raise up your trusty Red Ryder and fill him full of lead. Enjoy the vision. Avoid thinking that it might not happen the way of your dreams. Avoid thinking that the bear will be in the rough stuff that you can hardly see through, and that it's raining or snowing. Avoid the thought that he will be right there, right then, mad as hell from the 30-06 wound he got from some idiot four days ago. When he does show up, will you be equipped to knock him down with the one shot you're likely to get?