My trap and Skeet guns don't have slings/straps but all the rest of the hunting rifles and shotguns have "straps". I can roll the strap up and put it in a small ammo pouch on my belt. I don't believe in having a strap on the gun while hunting, the weapon should be in control in your hand(s). Now, after the game is down is a different story, and some other times as well, but generally the only time I use a "sling" is when I need to use my hands for something else. My slings have a piece of male Velcro sewn on it and on both shoulder pads on my vests and coats have the rug part of the velcro team sewn on. That way once it is on my shoulder it doesn't fall off very easily but by lifting the gun upwards the velcro releases. Another thing, I never carry the weapon on my back, or in over 50 years I may have had them on my back a few times, it is always, when slung in a sling, held in front of me, barrel pointing up, on either side never crossed, that way when I slip or fall by simply swinging my arm, and gun, outward it never cracks the back of my head or hits anything and is always controlled by the hand that holds it or it is easy enough to get it in my hand very quickly to control it's movement. I mean I am controlling the gun, not holding on to the sling/strap the gun is attached to while the gun swings wildly about.
"It's not the game but the chase ~ not the trophy but the race !" from my Dad, many years ago.