You know the little metal triangles that used to be used to hold glass in place in picture frames or windows? The Mississippi Parks Department scattered thousands of them around the Vicksburg, Corinth, and Champion's Hill battlefields to counter metal detection. Fortunately, today's detectors can discriminate.
The head stamp find looks like an old shotgun brass and the small item that appeared to have leather on it is a shotgun primer. It is from a very old shotgun shell. Instead of a plastic hull, it would have been made of paper or cardboard depending on the age. 1870's to 1900's were paper. 1900 to 1950's were cardboard. After 1950's to 1960's and later were plastic. We find alot of these here in the fields of NE Mississippi.