Kyle F

I took my 4 year old m2 apart this afternoon after a duck and noticed some orange inside the receiver that immediately caught my eye. It isn’t rust and looks as though a small piece of metal should sit there. I couldn’t find any pictures online to compare it to and see what should be there. Does anyone know? It doesn’t impact the action at all and doesn’t seem like a critical component. I take good care of the gun so I would’ve noticed this before. Pictures below.