Yes, there would be a lot of artifacts in that area. Almost 32,000 casualties (dead and wounded) over several days in May, 1864. You have some real history there.
The plunger looking pice is called a tompion if I'm spelling it right it used to have cork from top to bottom was used to plug the end of ur enfield rifle to keep rain and water out . here is the complete one alone and 2 broken ones I have found