I mostly use a leather rifle sling, carrying muzzle up with a piece of tape. I carry it in my right hand if I can though. If I’m in for a rough hike I’ll take my Eberlestock gunrunner pack and stow it in there.
Some of these slings people mentioned look like better options than the sling I’m using.
The best rifle sling holder, attaches quickly to any pack, holds any sling in place, offering a hands free solution while hiking. Simple, effective and affordable solution to keep your sling up on your shoulder when hiking with a backpack.
This along with a good rubberized sling seem to work the best.
The Gun Bearer does take a minute to get used to. I like having the muzzle up where I can keep track of it. It's much easier to manage trees, etc. A heavier rifle isn't as bad to carry, just adds to the overall load. However the pack becomes even more important shifting more of the load there.
A Safari sling. It goes across the back of one shoulder and the front of the other. By far the most comfortable way to carry. It also allows for a very quick shot if the opportunity arises. The only drawback is that your hunting buddy will want one, and his muzzle control may not be as good as yours. I've trained my buddy since he was 17, so it isn't an issue for me.
Ching Sling for accuracy. I'm getting older and the M700LR in 30-06 is heavier than an M14. I sling left shoulder, muzzle up, if somewhat sure I will have time to react. I carry sling assisted and at the ready if stalking in cover. I rest the rifle across my right shoulder, muzzle pointing back, with my right hand on the grip if I want to be ready and am still hunting for any length of time. The weight is on my shoulders and it comes off the shoulder and into the left hand quickly. I carry locked and loaded, with the safety off, unless I am climbing, fording, or in a slippery situation. I would have lost at least half the deer I have taken if I had to chamber a round. I would have lost a quarter if I had to take time to release the safety. I hunt alone from the ground and I figure that if I am pointing the rifle at myself, I should get shot for being an idiot. No tape. If I think there might be a problem I open the bolt and drain. I am supposed to know where the barrel is at all times and have not ever had to unplug a barrel since VN.