I too used the primos ,but like tdcour I couldn't get it to sling right with a pack on ,sights and stabilizer were always hitting on something making the bow hang almost upside down most of the time or the sling would fall off my shoulders I even got a heavy leather needle and sewed a big button on the shoulder strap of my pack, that fixed the slipping part but it just seemed to exaggerate tipping the bow up side down, so now I just strap it to my pack which keeps both hands free out of the way in thick brush , and finally figured out that if I was just hiking from point a to point b and jumped something I was already busted and had little chance to get a shot off anyway, so I've come to terms with it being strapped to my backpack!