I have found that shooting my ARs off the bench is an exercise in frustration due to the fact that they don't ride in the rear bag to my satisfaction. Short of spending what I though was an excessive mount of coinage to purchase a suitable stock I didn't see much relief to my frustration. So after a little brainstorming and thinking I came up with a thrifty (Cheap) solution that has worked out pretty well for me. It turned out to be a simple inexpensive solution for my needs.