Came across this Giles sling by Wilderness Tactical for $13, including shipping on ebay. This sling is designed for use on the Steyr Aug or Benelli M1 Super 90. They will work on other rifles as well. One of the best slings I have had the opportunity to use.
http://www.ebay.com/itm/111481902887?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.com/itm/111481902887?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT