Years ago I owned both a 6MM Remington on a Mauser I made, and later a 243 in a Ruger #1.
The best bullet I ever used back then in them for deer was the 100 grain Nosler Partition.
All of them I shot had exits. One shot by my friend Don was facing us and his bullet (Also a 100 grain Nosler Partition) went about 80% of the way through the deer and was found on the skin.

I have not used them myself, but I have seen Barnes TSX bullets used and they also gave the hunters exits. Deer antelope and several elk.
So if I were to get another 243 and hunt deer with it I think I'd choose one of those 2. Barnes TSX or Nosler Partition.