Many many options but packing a long range rifle and wanting quick access off a sling is iffy. I've seen options for a sling and a pack that allow quick carry to shouldered rifle but I've not messed with them. I run a team elk scabbard pack mainly and find it to be fine for what I do but I don't kick bush either generally. I can get to fairly quickly, not as fast as a shoulder sling or in my hands of course. I run cup mounts and qd sling on my rifle now and can configure the rifle for front carry, think patrol style carry for a M16, and it works fine. The issue with front carry is a bino harness does interfere a bit. I did use a harness style fanny pack for a long time and it works well enough and something you may consider if you really want to sling carry. This style of back pack incorporates a load carrying harness to distribute weight on the shoulders and hips, allows enough room for day pack essentials, and allows a user to run a sling system, and a bino harness is not negativily effected.