Hi Skull81,forgive the correction but what you have there is a point five heavy machine gun round also called a fifty cal,if I am right your P47 came from 495 FTG,Atcham,and crashed on a training flight,(near a wall at the edge of a forest)I too have one from a P47c5RE,416585,also from 495 FTG Atcham,headstamp DM 42,my round too was "inerted" as a result of the crash,pilot bailed landed in a tree uninjured,have you visited Fort Perch Rock museum,the tailwheel assembly from my P47 used to be on display there,
Regards,
Don,