On Turkish snap-on nocks and bow tips 

Old Turkish arrows generally have very hard snap-on nocks. This video shows how they work, and why.
All equipment made by the presenter, Ivar Malde, at the one-man company "Kviljo Buemakeri" (bowyers workshop, in Norwegian). Ivar holds four official world flight records, including the worlds longest shot with all natural material bows and arrows, at 566,83 meters. Bows and arrows like these can be ordered via www.kviljobuemakeri.org