You need to decide just what and how much you want to carry first. As little as possible is a good rule.
I use a Bianchi Endurance pack at 800 ci to my Kifaru Spike Camp w/ 2200 ci plus with add on pouches. Depends on the weather conditions and what I need to hunt with.
Things like extra clothing, particularly if you sit for a while in really cold weather, to food, optics like binocular(s) or a spotting scope, and the head and meat of a kill.
Kifaru makes a Gun Bearer system that can be purchased separately for use on other packs. Easy, and fast to use, allowing one to free both hands for rough going.
If you are planning on carrying much weight, be sure to get a pack that is properly designed for that. Such packs cost alot more but are really worth it in rough, steep country. E
