I'll be 84 in a couple of months. I shoot at least 3 times a week (precision airgun). I haven't missed the opening of elk season in the last 44 years. I've filled my elk tag the last 4 seasons, from 200 to 670 yds. So, at 67 you have lots of hunting years ahead of you. I killed several elk with a pre-war Mod 70 30-06. Now shoot a Mod 70, .300 WSM with a brake. 700 yds is my limit on elk, based on a minimum of 1500 ft lb of energy. My current load with a 181 gr Hammer Hunter, meets that criteria, as well as terminal performance. My second choice is the Federal 175 gr Terminal Ascent out to 650 yds. For elk, I'm a .30 cal fan, your choice of a Weatherby .30-06 is an excellent one. This forum is great place to learn about shooting, hunting and reloading.