I use a eberlestock
gunslinger and my 2 sons have Badlands. When it comes to packing a rifle with a pack you might want to look at a Kifuru GunBearer. These can be put on any pack of your choice that have a shoulder strap and belt. I have the built in option on the eberlestock and have not used it in the last 3 years except to use as a storage pouch. These things really work and are worth every penny - especially in really steep country where you need both hands or when your constantly using your binos. GUNBEARER
We're in Mt. and most of the time we bone out and pack out or meat - The kifaru holds your rifle and no interference with the meat.
I have tried every pack I can get my hands on that will hold your rifle in some way. After 10-12 hrs. you'll figure out what is comfortable.