I tried several options, and made a few contraptions, nothing worked well.
They either put weight on my neck and sagged, hot in the way of my pack waist belt, made the gun inaccessible, bulky, etc. I ended up going back to my military days and using the molle modular vest. I sewed loops on my bino case to quick release from the vest. It is comfy while wearing a pack, can be tailored to my particular hunt, and I keep it on all day long. I always have my survival kit, etc with me. The gun in holster fits over my pack waist belt. Here is a picture. It has been working for me...