I own a HW 110 but no sling on it, not that I haven't given thought to it, just haven't needed one as yet. Personal preference comes to play as far as sling material. I've found nylon tends to slip on the shoulder while woods-walking, leather is good all-around but the Quake rubber shoulder pad / nylon looped is the sling I tend to attach no matter what long gun I'm carrying.
So if I were to install a sling I would get a set of quick detachable sling mounts offered by numerous companies. These come with screw-in studs and detachable sling loops.
I've had my 110 stock off and there is plenty of material thickness out front to drill and mount a stud. Make certain to drill pilot holes centered on both ends of the stock and deep enough to accept the stud screw. Follow manufacturer drill size requirement and lube the stud thread with a drop of dish soap prior to insertion.
Hope this helps, Good luck.