If you're rifle is flopping around that much...
You deserve to get hit in the "boys." At least one hand, and positive control, on the rifle at all times. Then your boys are safe.
There's no way I'm hiking 6 miles into the backcountry without a comfortable sling on my rifle.
Why? Is seven or eight pounds really
that much of a burden?
The only time my rifle is slung when I am hunting is when it is too dark to shoot, or when I am dragging something out. For me, slinging a rifle is like throwing in the towel. It is an open admission that, for whatever reason, this hunt is over. Most of the rest of the time, the rifle is carried against my chest.
I shoot left-handed, so I find swinging from left to right, across my body, is fastest. My brother is right handed, and as he is my most frequent hunting partner, we have gotten in a habit. During the summers we walk these tracks near my grandpa's property for miles with rifles. The rifles vary. Sometimes we carry a .22 and a shotgun. Other times, we take our AKs, or SKSs. Lately I've become fond of my M1A and carry it pretty much everywhere I have to opportunity to do so. But in the past we've carried our hunting rifles as well. And all we do is walk these tracks for several miles shooting ground squirrels in the berms next to the tracks. We walk online, him on my left. Anything in the middle is first come first serve. Anything to the right, or anything that runs to the right, is mine, as it is easier for me to track in that direction. So on and so forth.
During these walks, we've worked out our own individual systems for carrying our rifles for miles on end without too much physical discomfort. The best way I have found is to keep it close to, but in front of, the body. Therefore, I carry my M1A and my hunting rifle both flat against my chest, muzzle to the right, away from my hunting partner. I touch my thumb and middle finger of my right (support) hand around the grip of the rifle with the forend nestled in crook of my elbow. The sling is pulled taught up front and pinched between my arm and the stock. The pinky of the support hand pulls in the sling just in front of the rear swivel. In this manner, both ends of the sling are tight and controlled, so there is no squeaking swivels. The rifle is held tight to the chest with the arm in the same position it would be in if it was broken and in a sling. The left (shooting) hand can then "hug" the chest, if necessary, to reduce fatigue on the support arm by simply grabbing the support arm elbow with the shooting hand and pulling both arms tighter to the body. Using this method, I've fond I can carry either my ~12 lbs loaded M1A or my ~9 pound loaded Rem 7mm Rem Mag pretty much all day without physical discomfort.
I've fond this position brings the rifle into action faster than when it is slung as well. When need, the support arm simply pops the forearm up as the firing hand takes control of the pistol grip. My dad carries his rifle slung safari style. He was the only one in our family that did this, and it earned him the reputation as the man to beat getting one's rifle on target fastest in the field. He's got a lot of years of practice on me carrying it in this method and he is indeed very fast, though he laments constantly about how much faster he was when he was young and woolly. But I get on target faster using my method that even he does.
This has gotten very long-winded, I realize. All I am saying is I see no reason to ever have an active rifle slung.