I haven't shot any deer with any of the .243's I've owned, but load deer rounds in that caliber for my grand-kids. I used Barnes TSX 85 grains a couple of years ago and grandson #1 shot a nice doe at 150 yards high in the heart-lung area and the deer was dead when it hit the ground. That's decent performance in my book, especially when I was concerned that it might not expand adequately on that type of shot.
For deer, I now load only Hornady GMX bullets in my .270 Win and .243 Win. Being hollow-point gilding metal bullets, they expand well and we don't have to worry about lead in the deer meat, or in gut piles that eagles or other scavengers might eat.
“God save us from people who mean well.”
― Vikram Seth