Found these this weekend. They were along a creek used for storm drainage. It's and old park and had activity during the Civil War. These hit 91 on my AT Max. From the sounds of it there are more, but after digging two of them I stopped chasing them. Please enlighten me if you have an idea of what they might be. I also found some other metal debris and signs of a structure in the area. They are solid and light weight. Maybe 4" to 4.5" long.