The "Best" big bore cartridges ever created!!!

[Tug]

The Best, is easy for me
500 A2-simple. 460 Weatherby brass (which is great) fire-form, load 98-100 grains of Varget, 570 grain Barnes X
My rifle BRNO 602, mine started as 458 Win, action needed no work, Bell & Carlson stock, steel picatinny rail, TPS rings, Nikon Slughunter scope

Did you have to change the bolt face diameter?

 

[MLindsay]

Did you have to change the bolt face diameter?

yes, did not have to do anything for action to feed cases

 

[Northern Shooter]

I wonder how the 450gr 458WM (Barnes) load compares to the full power loads? Velocity is 2,240 fps, energy is 5,115 ft-lbs.

Here is loading data.

Barnes Powder Charge

 

[skydiver386]

Ballistic studies are always enjoyable and there is plenty to learn if you approach things with an open mind.

Whenever you put the word "Best" into any discussion, it helps to narrow things down to not only specify game species, but what type of shot, ie Elephant brain vs body shots.

The .375 H&H is always going to be a favorite for Dangerous Game, and easily the best all around cartridge for hunting Africa, but would not be the first choice of many on this forum for body shots on Elephant.

Another factor mentioned by @Mark A Ouellette is the particular bullet used. When manufacturers design a bullet, they often have no idea what cartridge it will be loaded in, what game will be hunted, at what distances, or any other factor that will effect it's performance. In the .308 dia., factories tend to use 30-06 velocities a baseline for designing that caliber. Their Premium 150 grain bullet may be used by handloaders in a 14in 30-30 T/C Contender pistol, or a 26in 300RUM, yet customers will expect equal performance from both.

Selecting the "Best" should obviously start with the species being hunted, then the recoil that particular hunter is capable of shooting accurately, then the bullet most suitable for that game under conditions of that hunt if possible.