i use a "super sling" in 1" and 1 1/4" both. it is made by "outdoor connection" and sold at walmart or other places as well. it is a standard nylon rifle sling, but shortens up real well. it comes in brown, black, and different camo versions.
i hold the forearm with my left hand, right hand on the grip of course. i let the sling droop down n around my left elbow. i then push outward with my left arm to apply tension n steady up.
the "just sling it" sling is another option. "southernutah" over at specialty pistols site is the original inventor of that n may be able to help ya out there. "eabco" used to sell that sling as well. ya might get a look see at it at that site.
a internet search should be handy