Infantry I button is for scale purpose (and bragging rights). The three other items were found in civil war camp...
1) Carved bullet? What was it carved for? Picking action implement/tamping?
2) Brass riveted nailed item? It seems it went thru wood. Nails were tapped at end and capped.
3) Small brass. It is light. It doesn?t seem to have been a cartridge or carbine.