People always talking about a .275 or a .308 or a .375 if shot well and penetrating the brain, breaking the spine etc aren't talking about a stopping rifle.

Of course a 900 gr bullet or a 175 gr bullet penetrating the brain well will kill an animal.

A stopping rifle isn't about good precise bullet placement. It's about rushed shots, charges, missed brains, body shots. It's about knocking a lion down, a leaping leopard, a buffalo heads down at close range, an elephant coming fast, in the O,d days arhino with itshorn in the way.

It's about flattening the beast, stunning it, raking it from end to end, shoking it's brain, causing massive muscle, tissue and organ damage.

I remember a PH telling me a .500 Asquare was useful for flattening a lion "boiling out from the bush". He also had a .460 Asquare. The .500 was better he said for flattening an attacking lion.

A .375 solid to an elephant's or buffalo's brain will kill it. A miss on the brain might not even cause it to flinch, especially the elephant. A 570 gr .500, a 750 gr .577, a 900 gr might crack the skull, stun the beast, even kill it. At the least might give time for the killing shot.

No one flinches on the internet, so recoil is never a problem. So of course a lesser recoiling rifle is a better choice if one has nothing else, or can't handle a very heavy recoiling rifle. A well aimed shot is always better than a flinched miss.

For the cool superbly practised shot, a .375 or a .275 or .318 can be a stopper. Mere mortals need help and a hammer.

For me a stopper begins at the .450s, and preferably a .500. A thick bush or scrub rifle for DG is the same.

Unless one has a gun bearer, the modern world is a world of compromise. A client or self hunter can only carry one rifle. The usual choice is the .375 to .450 range. If specific on buffalo, elephant etc maybe something larger.