RE: what caliber do you use
Hmm,
I don't pursue deer anymore; however, when I left off, my favorite set up was a long barreled 338WinMag with a Leupold 2-7. Range varied from 25 feet to 300 yards with 150 yards being common.
This was my favorite rifle for hunting anything and everything at the time, regardless of size. It seemed when I "pulled down" on my quarry and fired it died immediately and that was it. This was before I diversified my rack of rifles a bit and the 338WinMag just kind of crowded my .270 out of the picture, even for antelope. Kind of fun recollecting all the good old "bambi popping" days --- thanks!
Good Luck and Good Hunting,
EKM