Hmmm. I have witnessed bullets coming apart in both the .243 and 6mm Rem. The deer were recovered, but poor performance in my book. One was a neck shot and the deer got up a few minutes later and started to stagger off. The bullet had come apart before it could break neck bones. Mind you this was a buck in the rut so his neck was pretty well swollen up, but still, I think a .243 should be able to break a deer's neck. Range about 80-90 yards. I can't say for sure what my friend was shooting, but he has a hodge-podge of factory loads and I'd guess it was a lighter one. The two of us had to heave pretty good to get the buck in the pickup and I'd wager it was at least 150 lbs, maybe closer to 175.
My wife shot a decent sized doe, which for us is a hundred pounds or so, through the shoulder on a broadside shot. The bullet broke apart on the shoulder but a piece of the bullet or bone severed the spine, so it was DRT but could have easily been lost. This was with her 6mm, range about 90 yards or so. We aren't using that load anymore unless it's for varmits.
Anyway, putting out that info as a lead-in to my philosophy which is bullets really ought to be able to go through a small whitetail, if needed. We also have lots of pigs to shoot and bullets definitely need to be tougher for those.
For deer, we have had pretty good luck with factory Remington 100gr. Core-Lokts. They will go through our deer, no problem, and penetrate 14" - 16" inches on pigs, which is OK. I need to get some handloading going for the 6mm but it might have to wait till after deer season.
If you can find the Federal Premium load with the 100gr. Nosler Partition bullet, I would suggest that as the best all-around factory load. While I haven't used 6mm Partitions, I have used them in several other calibers with no issues. The front core tends to fragment pretty easily and will make a mess out of lungs. The rest of it will drive on through and you should have a blood trail if it isn't DRT.
Not a real big believer in DRT myself, have seen some animals run off with unbelievable damage... like to have a blood trail if needed.
Best of luck.