Dunno what kind of pack you have but....
We hunt with external frame packs and I hate carrying a rifle in my hands - use a walking stick. I strap my rifle across the uprights of my packboard using 2 quick release straps. They are snugged down very tight so the rifle doesn't flop around. This is my method for hunting open country and, contrary to public opinion from cheechackos, you don't find a bear behind every tussock and boulder here in Alaska. You would be surprised how fast you can get your packboard off your shoulders and access your rifle.
The rifle stays on the packboard even when we stop to glass for caribou or sheep. If you see something, just unsnap it and go after your quarry. A very simple and inexpensive setup.
Bear in Fairbanks
"Unless you're the lead dog, the scenery never changes."
Amazingly, I've lived long enough to see a President who is worse than Carter.
And finally,
Gun control means using two hands.
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