I have shot three cape buff straight through the heart with a .458 Lott, all with 500 grain soft nose bullets, and all at close range.

That is a small sample, and the Lott is not the biggest of big bores. But none of those buff died instantaneously. All ran the prescribed distance, more or less. One was dead when we walked up. The other two would have died, had we let time pass. But we didn't and I put in finishers.

And let me add that while the Lott is not the biggest and baddest of calibers, neither is it a minor one. Quite the contrary, the Lott is a crusher. And each of my buff, with big flaming holes through their hearts and their heart-enveloping lungs, flinched, humped up and limped, and then still ran like wind the fully prescribed heart-shot distance, more or less.

That direct experience, scant though it is, plus the reams I have read and heard of on this subject, have informed my humble opinion. Which is, again, that there is no way to guarantee that any caliber will drop and kill a buff on the spot without a CNS hit.

Still, I will readily concede that bigger is better, if the shooter can handle all that bigger entails, including, first and foremost, placing his first bullet well.