Set of Three Bullet Pendants, Dogtag Necklace, or Key Rings 223 Three Bullet pendants, three key rings, and three 24 inch Dog Tag Chains. 223 caliber, (5.5645mm NATO,)made from real bullet components, but completely safe. These are the most popular calibers because they are used in tactical firearms. People love these bullets so they make fantastic gifts. Ideal for gun enthusiasts, hunters, military personnel, video gamers, paintball players