For whitetail deer for 200 yds or under, I'd take .30-06 anytime. For Elk, which you may be taking shots out to 300+ yds, I'd recommend .300 WM or one of that family of calibers. It's going to shot flatter and with the .30 slug in a variety of types (e.g. Accubond, Failsafe, etc.) you'll get excellent penetration and expansion through boken and vitals.