A combination gun is good, because you have a quick second shot with a slug, where that is legal. I have a Leupold 2.5x20mm in claw mounts on my 8x57JRS / 16 gauge.
A single shot makes for a shorter rifle, while still keeping a long enough barrel. A Ruger No.1A in 7x57mm is a good all-around rifle. I had one, sold to a friend, now have .280 Rem.
I also have a Winchester M70 Compact in 7mm-08, with a Burris 1.25-5x22mm scope. This is a handy rig that is quick on target, and has reach for long shots.
A Browning BLR in 7mm-08 or .308 Win is just as short as my M70, and faster second shot. I have a 2-7x35mm Burris on it, but a 1.25-4x24 with German #1 would be even better for quick shots. Or a tactical 1-4x24mm illuminated like a Bushnell BTR-1.
All these rifles except the M70 Compact, and other stalking rifles - like the FR-8 Mauser - have iron sights. The scopes are in quick release mounts which return to zero. Some are open sights, some a Lyman 57 aperture sight which removes with a push button and returns to zero. Good iron sights on a rifle which fits you and the clothing are the light, slim, easiest to carry, fast to aim, and all you need out to 100 yards offhand, with a little practice. My scopes are accessories, secondary sights.