I have a Fab Defense GL http://www.fab-defense.com/en/category-buttstocks/id-208/m4-m16-shock-absorbing-buttstock.html
It has some sort of inner friction fit to make it fit either commercial or mil-spec tubes...I've had it on both and it was rattle free on both. Has a great 'tire tread' rubber buttplate that really grips the shoulder.
It has some sort of inner friction fit to make it fit either commercial or mil-spec tubes...I've had it on both and it was rattle free on both. Has a great 'tire tread' rubber buttplate that really grips the shoulder.


















































