Who says heart shots don't kill. 500 Grain Woodleigh from a Westley Richards .500NE . Big Hearts need big bullets.
Shot placement is the key preferably with a bullet of good diameter and weight , and unfortunately there is a whole generation of shooters ( I don't call them hunters, for shooters they are ) who have swallowed the hype of small bullets at high velocity, due I suspect, to the writings of many paid sporting authors , who have the belief that one only need to hit meat with a high velocity round to kill the beast. I have seen many people that bought high end rifles and all the gear, that could not hit a bull in the a*se with a hand full of wheat.
I have seen feral camels hit square on the shoulder at reasonable ranges with .338's only to have them bolt , moral, better to get a round into the lungs and usually more than one. Shot placement and knowing the physiology of the intended quarry is the best advice and yes if nothing else was available I would use a .243 on a camel but it would not be my choice as
adequate for camels, nor large deer. The .270 is the minimum calibre for Sambar Deer here , and I would argue that the .270 in the hands of 'shooters' is not
adequate.
I have owned one .243 in my hunting life, perfectly adequate for culling kangaroos and wallabies and shot many a feral pig but in my mind it was always 'lacking' so I traded it in on a .257 Roberts which allowed me to hand load 75grain - 120 grain projectiles which gave me more options over the .243 and velocity was not even in my thoughts.
Mike.