Checkout Stone Glacier - I've hunted with one for the last two years and swear by them. Bulletproof build - ultralight (3.5 lbs) - incredibly adjustable - has a large integrated meat shelf. Best pack I've ever used and that list is LONG!
I had an Eberlestock J34 that I used on my mule deer hunt last year. I sold it. It was o.k. but it would sag and sway too much for me. Also, the rifle scabbord was a bit of a pain in the butt getting my rifle into and out and keeping my gear secured in the pack. My rifle is a 12.5 #, 26" barrel 7 mm mag.
I am going with a Kuiu Icon Pro this year and plan on carrying my rifle along the side of the pack.
I may try to rig a Kifaru universal gun bearer on the Kuiu pack.
good luck