Randy759, if you do research on actual caltrops, you'll see that they ALWAYS have ONLY FOUR spines, which are arranged in a Tetrahedral pattern so that the caltrop will always sit with one spine pointing straight up, to impale a horse's hoof, a soldier's booted foot, or a tire. The objects with more than four points are absolutely not a caltrop, because you can't make it sit with one point straight up. Those are definitely a form of Tumbler-Media known as "Mill-Stars," used in a tumbler-mill by the Metalcasting Industry to remove burrs and sand from raw-cast metal objects. They've been discussed in TreasureNet's "What-Is-It" forum several times. Two TreasureNet members have reported they've used those 6-pointed Mill-Stars in the Metalworking Shop at their job. About the ones found "near Missionary Ridge"... the Chattanooga area has historically had several ironcasting foundries, where Tumbler Mills are used to "finish" the raw castings.
The photos below show a Roman-era caltrop, and World War Two caltrops. Note that they have only FOUR spines, arranged in a Tetrahedral pattern so that they'll sit with one spine pointing straight up.