This video may have some relevance to this thread. Some....perhaps...
A shooter tests penetration of 4 various Remington or Winchester factory loaded cartridges into 10 lined-up 1 gallon water jugs.
30-30 170 grain Remington Core:Lokt
308 Win 180 grain Winchester Power Point
30-06 180 grain |Win Power Point
300 Win Mag 180 grain Power Point
Which one had the most penetration? ( = "best blood trail"?).
Guess before you watch.
https://www.youtube.com/watch?v=VlzKM8VSRqcps: I edited this post late for the 30-30 being a Rem Core-Lokt, not a Win Power Point.