They also make the mistake of showing the dart's blunted, fletched end being placed inside of the hook. In reality, the dart has a cupped conical depression drilled into it, possibly with sinew or other reinforcing fiber wrapped around it to stop it from splitting as easily with repeated throws, this depression fits over the spur. As the atlatl is swung. keeping the dart level with the eye for accuracy, this cup and spur creates a bearing system that helps propel the dart down a narrow arc and release just after the apex of the throw, though following through the motion of the throw is still important.

This is a sweet a** video for what appears to be a small group making this haha.