I see your point. However, as mentioned before, the .500/.416 does that, and is an interesting case study. The .450/.400 3 1/4" NE gave a 400 grain bullet a true 2150 fps in 26" barrels (it was standardized in 26" barrels and the factory ammo actually did it, while the other flanged nitros were standardized in 28" and longer barrels). The .500/.416 standard spec is a 410 grain (and thus the same SD as the 400 grain .400) at 2330 fps in 25.5" barrels. All the rifles I've handled and shot have been 23.6", not 25.5". I chronographed several batches of Krieghoff factory ammo in a new Krieghoff a while back, and average vel was 2250-2260 fps. The .500/.416 gives a 100 fps increase in real rifles, but has to use a larger .500 basic case with 20 grains more capacity to get it, yet still can only do it with higher pressure, despite the factory ammo being loaded with blended (more than one powder) non-canister grade propellants to control burn rate and keep the pressure down. It seems a reasonable assumption that handloaders limited to single canister grade propellants can expect the same results only at the expense of even higher pressure. Again, the result is a DR that is rightly perceived as higher pressure than the others, and offering no advantage in weight or recoil compared to the .450/.470 class rifles. More velocity is expensive, and not needed.

Choose your "writers" carefully these days. Genuine, wide experience with elephant belonged to generations gone. Modern "experts", especially of the internet variety, have almost no experience by comparison, especially with a variety of rifles.

Personally, there are just some animals that I've never had any desire to hunt, with lion (used to raise 'em) giraffe, and especially elephant at the top of that list. I've followed that argument that you mentioned though, and it's as old as the hills. John Taylor discussed it in considerable detail 60 years ago. In his "summing up", for the heaviest thick skinned dangerous game (his class c, not as an all rounder) he recommended the .400 and .465. He went on to say that he would be just as happy with a .400, and only mentioned the .465 to recommend it from it's kin in the event someone just wanted something bigger (which he clearly meant to mean someone who needed a boost to his confidence). Taylor made his living hunting elephant, and was far from alone in his views on the matter. He said that, in his experience, you only heard the ".450 minimum" argument from those who bought into it, went that direction and had no problems, and then insisted that the .400 was too light despite having no experience with it at all. Nothing has changed. I've never heard anything but high praise for the .400 from the guys I know who have actually used it on elephant.

Sure. The .404 (the original standard load, which duplicated the .450/.400 3") was adopted as standard game department issue in Kenya, Tanganyika, Northern Rhodesia, and Southern Rhodesia. It probably saw more use on elephant than any other cartridge of it's time, was used under every condition imaginable, and gave sterling service. As Pierre van der Walt says - "One can actually stop at that, as it ends all arguments." He goes on to say "In original Cordite configuration, the cartridge launched a 400 grain bullet at 2,125 fps. Unlike humans that grow softer with each generation, African animals seem to grow tougher, because this moderate velocity load proved immensely effective in Africa - whereas modern hunters believe it a squib load."