The caliber is not near as important as the bullet you use. As explained above, fragil bullets at high velocity will either fail and not penetrate or blow up a lot of meat. I like the middle bullet weights in the middle caliber and control meat damage with shot placement. If I am up close I will take a head or neck shot. If its important to drop the deer in its tracks, I like a high shoulder shot. I mean right at the top just over the main shoulder blade. This will miss the loin but damage the spine area enough to usually plant them right there. This will also disable the shoulder and generally tip them over right away. In a big magnum rifle I would use the heavier bullets. At least 180 grain if not 200 in the 30 calibers and something like the 160 grain in the sevens. They won't open quite as quick and do less meat damage as a rule. Back when I had magunietes I shot quite a few deer with the 300 Win Mag with 180 grain bullets. They do however NOT kill a deer any faster than my 260 or 257 Roberts. I don't like to waste any meat as the meat is top priority to me. I would never need anything bigger than the 257 Roberts or 25-06 and 260. In these I use 100 grain bullets in the 25's and 120 grain in the 260 and 280. I think the Nosler partition is the best bullet for sure kills and minimal meat damage. I would never need any Magnum rifle for deer unless I was in the positiopn where I had to shoot very lony distances. Even then on deer size game the 25-06 will do the same job.