I've shot deer with a 264 win, 260, 6.5 creed. 6.5 swede and several with various 30 cal. I've not had to track any with the 6.5s except for one buck that was running when I shot it with my 264 with a 140g Hornady interlock launched at 3200.
I first I thought I might have missed when we got to where it was and there was no trail. It was only about 150 yards out at the shot and wasn't running very fast so I followed the tracks in the dirt about 100 yards and found the buck dead. No blood trail but it was a high lung shot. It had about a quarter size exit but it was up high enough that the blood didn't really come out.
Several of my friends in Africa prefer at least a 30 cal claiming it leaves a better blood trail. I think there are too many variables to break it down.
One of the fastest dropping bucks I've shot was about 12 years ago. I just built a custom in 6.5 Creedmoor back before anyone was really making one. I hit a nice 4x4 muke deer at about 220 yards in tight right behind the shoulder. It dropped instantly and was done. There was a small exit where part of the bullet exited.
I also dropped another mule deer like lightning about 15 years ago with my little carbon barreled 260. That was with a 130g accubond at a MV of 2900 fps. That deer was running about 175 yards out when I hit it through the lungs it did a flip and crashed dead. That bullet did massive damage with a large exit. I still take that little 5 pound 260 loaded with the same 130g ABs as a back up on a lot of hunts.
Bb
