There are a few sling mounts available for an AR buffer tube. Make sure you get one that would clamp to the tube and not meant to go between the lower and the tube nut, as the 15-22 doesn't have one. I saw a 15-22 specific one someplace but dont remember where, it was also expensive. Another option is to do the same set up as the MOE and have a quick disconnect. You would need to drill and attach the quick disconnect tube in your lower. If I added a sling I would do it that way. But the 1st option is easiest.