Last year I shot two deer with 70gr TSX .223 rounds. One was from my 24" heavy barrel 1:8 twist. It definitely did it's job. The second doe I shot , in my lack of judgement, used the same round from a 16" 1:9. It keyholed, but somehow traveled up the deers neck and ripped open a line under the deers "chin". I got lucky there that it killed it, though the deer did a 2-3 minute death roll. Both had blood every where.
This year I have been using 150gr tipped TSX with a 16" .308. I shot at one, swore I should of hit it, found no blood, never found anything. Second deer I hit, but could find no blood around where I shot it at. It was standing in the middle of the road (private road, dirt, through hunting club, not a public road) but I found no blood in the road, or on the side of the road. I found it 30 yards off the road dead but was surprised at the lack of blood I found. The entrance wound was hard to find, no blood at all, about the size of a .22LR bullet. The exit was around a dime size hole so I guess it did expand but the lack of blood concerned me.
Shot a third, didn't find anything either. I'll admit I may have missed this one as it was a 100 yard shot between two trees but it just bothers me I keep shooting at deer and finding no blood at all. Either I developed a flinch or they just aren't performing the same as I expected. I don't have my 24" 1:8 .223 any more but I may switch back to my 16" AR with 62gr TSX.