When in dense bear country I carry both bear spray and a shot gun, each mounted to the daisy chains on the side of my pack in a way which allows fast and easy access,without possibility of snags and hooking up.
I mount bear spray on the left side, attached with 2 shock cord loops around the container, near the bottom of the pack on the side-most daisy chain. Pulling it out is much easier in a downward direction so I attach the cannister upside down so when I pull it out reaching backward with my left hand, is is upward in my hand and ready to shoot as i bring my hand forward.
Mys shotgun is attached to the right side and I retrieve that reaching back over my shoulder and pulling the pistol grip up and over my shoulder.
I have to remove my pack to reattach both.
Edit: I am away from most of my expedition gear right now, but when back in Labrador, I will attach it all and send a few pics - in about a week.