I learned two things, which I actually already knew:
#1. When in dangerous animal country, carry your rifle with a safari sling, across your chest......the rifle is more available, it seems to make it lighter and it leaves your hands free.
#2. Have a backup handgun, of sufficient power, in a chest rig (Kenai Holster).
All based on the simple principle that your hand (arm, elbow) can most easily move to your chest to access a weapon.