I'll echo what a few have already said: Magpul MS4 with attachment points at the rear of the receiver and another out front at the end of the rail. Easy 1 or 2 point conversion depending on the situation. I've tried more than a few slings and while I don't run a gun for a living I have spent some time wearing them and this is what I prefer. 2 point for travel and 1 point when shit gets real seems pretty good to me.