Zero issues with deer hit with well-placed 243 bullets. If you're hunting them "afoot" and taking the angles that are given by obstructions... maybe sometimes the answer is just not to shoot... rather than depend on a bigger bullet to make up for placement. That's not a criticism of how anyone hunts or what with... just an observation.
I've killed several deer with 100 grain CLs in 243. None of them went anywhere. On the other hand, I shot a deer a few years ago at about 50 yards with a 6.5mm bonded bullet, turned both lungs and the heart to liquid, but the damn thing still ran 40 yards into the thickest stand of blackbrush in Texas before hemorrhaging (looked like the bucket of blood scene from Carrie) everything in the chest cavity and falling over. Sometimes deer are just gonna run dead on their feet.
There's certainly nothing at all wrong with taking angle/quartering shots that go through vitals. If you're worried about a 40-50 yard death run making a deer "nearly impossible to find" you should probably stay in your stand whereyou can pick your shots.
You quoted "nearly impossible to find" ... but I didn't actually say that. I followed a blood trail and dragged the deer out. (Obviously, or I wouldn't have know what the hemorrhage site looked like.)
In your previous post, you implied that the 243 wasn't enough gun because the way you hunt doesn't allow you to select shots given the angles and obstructions, so you'd prefer a larger cartridge. But if you're capable of really putting a bullet through vitals, what's the problem with shot selection? We aren't talking about elk or bison or a brown bear skull. If you have a shot at vitals, for a whitetail, the 243 with a good bullet will get the job done just as well as a 6.5 or 7mm, as virtually everyone here has stated.
I never implied a .243 wasn't enough gun. With the exception of rio ,I've probsbly killed as many with a .243 as most anyone else here. It won't put deer down on the spot dependably with a lung shot, nothing shoulder fired wiil. It also won't put as much blood on the ground as often as a larger cal. IME and for that reason I prefer to use something with a bigger hole in the muzzle when hunting in cover and not from a stand. For stand hunting where you can pick your shots, a .243 or even .223 is fine.
