I have scads of packs, mostly for canoe trips, but have acquired a variety of backpack packs from Granite Gear (since they are made here), and two dedicated hunting packs. My go-to for years was the Eberlestock J34 Just One. It is heavy, just by itself, and i find that I just keep stuffing it until full, but can carry 70# plus without a problem. I do try to keep it under 55# for a pack-in hunt. The downsides are that I don't care much for it as a day pack because of the thick shoulder straps (in case I have to shoot while wearing it), and I about killed myself once packing out a mule deer as the boned out meat worked its way far enough down the pack to butt bump me with every step. I have learned to cinch the bottom of the pack almost closed to carry the boned out meat higher.
I bought an Eberlestock Mainframe and plan to use it on the backpack DIY cow elk hunt this year. The duffle from my J34 zips in and should allow me to pack in what I need. With just the batwings it seems like a good daypack option, and the meatshelf should be an improvement over a soft bottom.