RE: 7mm-08?
The 7-08 is a very fine cartridge.....however the question about blood trails and how far they run is not a matter of cartridge, it' s a matter of ammunition and shot placement.
Personally, I recommend a bullet that leaves an exit wound. It helps with a blood trail and it usually drops deer in their tracks. Equipment is just one equation....placement is another.....you need to do your job first.