the major problem with the 458 Win. was the original ammunition.
This squares well with what I have heard. The original solids did not perform as well as they should have.
according to stories I have heard, things got changed after Joyce Hornady went on safari, and heard the complaints firsthand, from people who used them, and had no idea he was the guy supplying the bullets to Winchester for their .458 ammo.
When he went home, he redesigned the jackets and the .458 got much better.
Don't know if this is true, but it does make a good story.
For solids to work right, not only do they have to be built right, but they also have to impact within the right velocity range. Too low, and obviously its not enough to penetrate the heavy bone (elephant skulls). But too FAST and performance also suffers. The bullets tend to glance off rather than punch through. The best range appears to be from about 1900-2200fps.
This is not a situation encountered in North America very often, although it does happen when things are just right. I was with a party once where a black bear was shot 5 times in the head with a .30-30 at close range. Every shot but the last one, the stars were in alignment for the bear, and the bullets glanced off, due to the angle and curvature of the skull. The last shot struck at the right angle, punched through and dropped the bear, a few yards from the shooter, who promptly returned to camp to change his pants...
I don't recall if it was in Death in the Long Grass or one of his other books, but I do remember Capstick telling of the time when as a cropping officer, his .458 failed, and only quick action by his gun bearer saved him.
He had made a habit of reloading over the last round in the mag. The idea being that if he got charged while reloading, there would always be one round there to use. The one time he actually did need it, he made his shot, bullet struck in the right spot, but didn't drop the elephant. His bearer distracted the beast with a water bag (high drought season), he rolled away, reloaded and dropped the elephant.
Now, that was impressive to me, but what really impressed me was that afterwards, to find out what happened, he fired 10 shots (as he had cropping that day) into a termite mound, reloading over the same round every time.
Then he looked at the "emergency" round and saw the bullet had been pushed deeper into the case by the battering of recoil in the magazine.
Compressed powder, higher than intended velocity, the bullet glanced off, rather than penetrated.
I love reading the stuff, because I will never live it. Besides the money, I simply don't have the guts to hunt Tantor like that.