I use 550 paracord to hold my sling rear connection point. It has worked great. Best of all it's very cheap. I use the Emdom Gunslinger sling. It is also available at skdtac.com and they ship to most nations. They also have other slings and even the Midwest Industries and Daniel Defense mounts that work with the 15-22.





You could also try the Stark SE-2 pistol grip. It has a built in quick disconnect (QD) socket on the rear for a QD swivel. Since the 15-22 has a molded trigger guard, you might only have to cut the trigger guard from the Stark grip.