I recall a hunt report where a body shot was taken on an elephant with a 458 Lott. By the time the shooting stopped I believe it had some 3000 grains of projectiles in it. And it ran some 13 miles and all night.
The next morning it was dropped at 12 yards with a frontal brain shot.
Upon butchering the beast, it was found the first shot had put a groove in the heart but had not cut it open.
A resident (of this site) commented that the hunter should have converted his 458 Lott to a 470 Capstick! And that if he had, the extra but diameter would have surely split the heart open and the elephant woukd have died within a few yards.
Ok, so the extra 8 thousandths of an inch diameter "may" have split that heart open. Provided the center of that bullet hit the same spot. I would contend that is a near impossible feat. A different barrel, slight different recoil. Maye a twing of flinch, hell variation between shots!
Sometimes we get carried away with our mathematical computations and go well beyond reason
So, therefore you should immediately scrap your plans and investments to date and immediately order a 470 Capstick barrel!