I've been considering using a single "Button Sling" from the Web site below....  I did a search of the forum for Button Slings and found nothing...  If you have any experence with these slings, please share your experence....  I have a Colt Upper on a Cavalry Arms lower.  The Cav Arms lower does not lend it's self to a single point type sling, except when using the read take-down pin.  Thanks, Helopilot.

http://www.buttonsling.com/pg5_tactical.htm