My Dad, brother, and I will all three be using .270's. IMHO The PERFECT round for deer. Dad's hunted with his for almost 20 years, and calls her "The Meatstick" cause she's filled many freezers. Mine was inherited from my Great-great Uncle C. I'd be willing to bet that rifle has taken more deer than most folks have seen. I call her "Buster". Last season I took 2 nine point bucks, 2 does, and 3 Turkeys with her. My brother is a lefty, and finally bought himself a left handed model last week.
We shoot 130 grn Core-Lokt, cause it's cheap, effective, and always readily available.
If I get a close shot, I may try the .45 (Sig P220) this year.