J. Whittaker: Part of a kit of tools used to make and repair atlatl darts - bannerstone is spindle weight to spin string and taper dart shafts. Experiments to show it works - need cordage for whipping dart shafts and attach fletching. Used as flywheel on bowdrill arrangement to spin shaft while using abrasive in leather to round and smooth dart shaft. Bannerstones are designed to spin, and holes range from too large to too small for atlatl, and too heavy. [These last are unsupported assumptions and contradicted by other experiments, but the basic idea is reasonable and shows how replicative experiments + archaeological evidence can still remain equivocal].