RE: Gun Sling
Well, I use a cuff sling for hunting, but I don't think I would use one on a shotgun at 125 yards. Tactical Specialties makes the best cuff sling I've seen. It is really great for 300+ yard prone shooting. The buckle makes it great for a quick attach when antelope hunting.
For deer hunting in a stand, I think I would use a hasty sling fro 1.25" webbing. When your barrel is pointed up, the tension is off, but once the gun is pointed, the tension can be quickly applied.